cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Near Infrared Spectroscopy of Young Brown Dwarfs in Upper Scorpius
Creators: name: Dawson, P.
name: Scholz, A.
name: Ray, T. P.
name: Peterson, D. E.
name: Rodgers-Lee, D.
name: Geers, V.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Spectroscopic follow-up is a pre-requisite for studies of the formation and early evolution of brown dwarfs. Here we present IRTF/SpeX near-infrared spectroscopy of 30 candidate members of the young Upper Scorpius association, selected from our previous survey work. All 24 high confidence members are confirmed as young very low mass objects with spectral types from M5 to L1, 15-20 of them are likely brown dwarfs. This high yield confirms that brown dwarfs in Upper Scorpius can be identified from photometry and proper motions alone, with negligible contamination from field objects (<4%). Out of the 6 candidates with lower confidence, 5 might still be young very low mass members of Upper Scorpius, according to our spectroscopy. We demonstrate that some very low mass class II objects exhibit radically different near infrared (0.6 - 2.5micron) spectra from class III objects, with strong excess emission increasing towards longer wavelengths and partially filled in features at wavelengths shorter than 1.25micron. These characteristics can obscure the contribution of the photosphere within such spectra. Therefore, we caution that near infrared derived spectral types for objects with discs may be unreliable. Furthermore, we show that the same characteristics can be seen to some extent in all class II and even a significant fraction of class III objects (~40%), indicating that some of them are still surrounded by traces of dust and gas. Based on our spectra, we select a sample of objects with spectral types of M5 to L1, whose near-infrared emission represents the photosphere only. We recommend the use of these objects as spectroscopic templates for young brown dwarfs in the future.
description: 12 pages, 9 figures, Accepted in MNRAS
Mechanism of basal-plane antiferromagnetism in the spin-orbit driven iridate Ba2IrO4
Creators: name: Katukuri, Vamshi M.
name: Yushankhai, Viktor
name: Siurakshina, Liudmila
name: Brink, Jeroen van den
name: Hozoi, Liviu
name: Rousochatzakis, Ioannis
Publisher: name: arXiv
Year: 2014
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: By ab initio many-body quantum chemistry calculations, we determine the strength of the symmetric anisotropy in the 5$d^5$ j $\approx$ 1/2 layered material Ba$_2$IrO$_4$. While the calculated anisotropic couplings come out in the range of a few meV, orders of magnitude stronger than in analogous 3d transition-metal compounds, the Heisenberg superexchange still defines the largest energy scale. The ab initio results reveal that individual layers of Ba$_2$IrO$_4$ provide a close realization of the quantum spin-1/2 Heisenberg-compass model on the square lattice. We show that the experimentally observed basal-plane antiferromagnetism can be accounted for by including additional interlayer interactions and the associated order-by-disorder quantum-mechanical effects, in analogy to undoped layered cuprates.
description: 8 pages, 2 figures
Appearance of innermost stable circular orbits of accretion discs around rotating neutron stars
Creators: name: Torok, G.
name: Urbanec, M.
name: Adamek, K.
name: Urbancova, G.
Publisher: name: arXiv
Year: 2014
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: The innermost stable cicular orbit (ISCO) of an accretion disc orbiting a neutron star (NS) is often assumed a unique prediction of general relativity. However, it has been argued that ISCO also appears around highly elliptic bodies described by Newtonian theory. In this sense, the behaviour of an ISCO around a rotating oblate neutron star is formed by the interplay between relativistic and Newtonian effects. Here we briefly explore the consequences of this interplay using a straightforward analytic approach as well as numerical models that involve modern NS equations of state. We examine the ratio K between the ISCO radius and the radius of the neutron star. We find that, with growing NS spin, the ratio K first decreases, but then starts to increase. This non-monotonic behaviour of K can give rise to a neutron star spin interval in which ISCO appears for two very different ranges of NS mass. This may strongly affect the distribution of neutron stars that have an ISCO (ISCO-NS). When (all) neutron stars are distributed around a high mass M0, the ISCO-NS spin distribution is roughly the same as the spin distribution corresponding to all neutron stars. In contrast, if M0 is low, the ISCO-NS distribution can only have a peak around a high value of spin. Finally, an intermediate value of M0 can imply an ISCO-NS distribution divided into two distinct groups of slow and fast rotators. Our findings have immediate astrophysical applications. They can be used for example to distinguish between different models of high-frequency quasiperiodic oscillations observed in low-mass NS X-ray binaries.
description: 4 pages, 2 figures, accepted by A&A Letters
The Wiretap Channel for Capacitive PUF-Based Security Enclosures
Creators: name: Garb, Kathrin
name: Xhemrishi, Marvin
name: Kürzinger, Ludwig
name: Frisch, Christoph
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: FOS: Computer and information sciences

description: In order to protect devices from physical manipulations, protective security enclosures were developed. However, these battery-backed solutions come with a reduced lifetime, and have to be actively and continuously monitored. In order to overcome these drawbacks, batteryless capacitive enclosures based on Physical Unclonable Functions (PUFs) have been developed that generate a key-encryption-key (KEK) for decryption of the key chain. In order to reproduce the PUF-key reliably and to compensate the effect of noise and environmental influences, the key generation includes error correction codes. However, drilling attacks that aim at partially destroying the enclosure also alter the PUF-response and are subjected to the same error correction procedures. Correcting attack effects, however, is highly undesirable as it would destroy the security concept of the enclosure. In general, designing error correction codes such that they provide tamper-sensitivity to attacks, while still correcting noise and environmental effects is a challenging task. We tackle this problem by first analyzing the behavior of the PUF-response under external influences and different post-processing parameters. From this, we derive a system model of the PUF-based enclosure, and construct a wiretap channel implementation from q-ary polar codes. We verify the obtained error correction scheme in a Monte Carlo simulation and demonstrate that our wiretap channel implementation achieves a physical layer security of 100 bits for 306 bits of entropy for the PUF-secret. Through this, we further develop capacitive PUF-based security enclosures and bring them one step closer to their commercial deployment.
Comprehensive Analysis and Measurement of Frequency-Tuned and Impedance-Tuned Wireless Non-Radiative Power Transfer Systems
Creators: name: Heebl, Jason D.
name: Thomas, Erin M.
name: Penno, Robert P.
name: Grbic, Anthony
Publisher: name: arXiv
Year: 2014
Subjects: subject: Other Computer Science (cs.OH)
subject: FOS: Computer and information sciences

description: This paper theoretically and experimentally investigates frequency-tuned and impedance-tuned wireless non-radiative power transfer (WNPT) systems. Closed-form expressions for the efficiencies of both systems, as a function of frequency and system (circuit) parameters, are presented. In the frequency-tuned system, the operating frequency is adjusted to compensate for changes in mutual inductance that occur for variations of transmitter and receiver loop positions. Frequency-tuning is employed for a range of distances over which the loops are strongly coupled. In contrast, the impedance-tuned system employs varactor-based matching networks to compensate for changes in mutual inductance and achieve a simultaneous conjugate impedance match over a range of distances. The frequency-tuned system is simpler to implement, while the impedance-tuned system is more complex but can achieve higher efficiencies. Both of the experimental WNPT systems studied employ resonant shielded loops as transmitting and receiving devices.
description: 11 pages, 16 figures. This article has been accepted into IEEE Antennas and Propagation Magazine
Krzysztof Wodiczko’s "Xenological Instruments", an Equipment for a City of Strangers: Urban Spaces and De-Alienation of the Immigrant
Creators: name: Scafirimuto, Guglielmo
Publisher: name: Cinergie – Il Cinema e le altre Arti
Year: 2018
Subjects: Video; Performance; Wodiczko; Immigration; Public Art

description: The article considers how the public art of Krzysztof Wodiczko’s acts as part of the discourse of political intervention in the urban space of marginalized people through technological and artistic media.

The analysis of his “Xenological Instruments” designed in the 1990s - and in particular their last version, the Mouthpiece (1995) –  focuses on Wodiczko’s “maieutic” work about immigrants in several international cities, and on his efforts to give them a voice and visibility in public space. Brought to different urban locations by “stranger’s” bodies, these “instruments”, which are technological prostheses with a portable screen, are able to stimulate the dialogue with local people opening the possibility of creating new democratic spaces of confrontation. Wodiczko audience interactivity outside the exhibition space of the museum, hoping to test the actual dynamics of our democracies and to charge his art with a “scandalous functionalism”.
description: Cinergie – Il Cinema e le altre Arti, No 14 (2018)
Attempt to describe phase slips by means of an adiabatic approximation
Creators: name: Berger, Jorge
name: Sardella, Edson
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: In the description of non equilibrium situations in a superconductor at temperatures far below its critical temperature, the Keldysh-Usadel technique (KUT) is required. However, the non-stationary KUT has not been applied to realistic circuits. Moreover, the stationary KUT has been applied in situations where time independence is not guaranteed. As a plausibility check for this procedure, we resort to a toy model (the Ginzburg-Landau model), in situations that involve very slow evolution. We find that, even in these situations, neglecting the explicit influence of time variation leads to inaccurate or even qualitatively wrong description of phase slips.
description: Co-author joined
Non-exponential decay in Quantum Mechanics and Quantum Field Theory
Creators: name: Giacosa, Francesco
Publisher: name: arXiv
Year: 2013
Subjects: subject: Quantum Physics (quant-ph)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We describe some salient features as well as some recent developments concerning short-time deviations from the exponential decay law in the context of Quantum Mechanics by using the Lee Hamiltonian approach and Quantum Field Theory by using relativistic Lagrangians. In particular, the case in which two decay channels are present is analyzed: the ratio of decay probability densities, which is a constant equal to the ratio of decay widths in the exponential limit, shows in general sizable fluctuations which persist also at long times.
description: Proceeding contribution for the symposium "Symmetries in Science", 21-26/7/2013, Bregenz (Austria). 6 pages, 2 figures
Online Learning to Transport via the Minimal Selection Principle
Creators: name: Guo, Wenxuan
name: Hur, YoonHaeng
name: Liang, Tengyuan
name: Ryan, Christopher
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Optimization and Control (math.OC)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: FOS: Mathematics

description: Motivated by robust dynamic resource allocation in operations research, we study the \textit{Online Learning to Transport} (OLT) problem where the decision variable is a probability measure, an infinite-dimensional object. We draw connections between online learning, optimal transport, and partial differential equations through an insight called the minimal selection principle, originally studied in the Wasserstein gradient flow setting by \citet{Ambrosio_2005}. This allows us to extend the standard online learning framework to the infinite-dimensional setting seamlessly. Based on our framework, we derive a novel method called the \textit{minimal selection or exploration (MSoE) algorithm} to solve OLT problems using mean-field approximation and discretization techniques. In the displacement convex setting, the main theoretical message underpinning our approach is that minimizing transport cost over time (via the minimal selection principle) ensures optimal cumulative regret upper bounds. On the algorithmic side, our MSoE algorithm applies beyond the displacement convex setting, making the mathematical theory of optimal transport practically relevant to non-convex settings common in dynamic resource allocation.
description: 23 pages
Automated Distance Estimation for Wildlife Camera Trapping
Creators: name: Johanns, Peter
name: Haucke, Timm
name: Steinhage, Volker
Publisher: name: arXiv
Year: 2022
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Artificial Intelligence (cs.AI)
subject: FOS: Computer and information sciences
subject: I.4.8

description: The ongoing biodiversity crisis calls for accurate estimation of animal density and abundance to identify sources of biodiversity decline and effectiveness of conservation interventions. Camera traps together with abundance estimation methods are often employed for this purpose. The necessary distances between camera and observed animals are traditionally derived in a laborious, fully manual or semi-automatic process. Both approaches require reference image material, which is both difficult to acquire and not available for existing datasets. We propose a fully automatic approach we call AUtomated DIstance esTimation (AUDIT) to estimate camera-to-animal distances. We leverage existing state-of-the-art relative monocular depth estimation and combine it with a novel alignment procedure to estimate metric distances. AUDIT is fully automated and requires neither the comparison of observations in camera trap imagery with reference images nor capturing of reference image material at all. AUDIT therefore relieves biologists and ecologists from a significant workload. We evaluate AUDIT on a zoo scenario dataset unseen during training where we achieve a mean absolute distance estimation error over all animal instances of only 0.9864 meters and mean relative error (REL) of 0.113. The code and usage instructions are available at https://github.com/PJ-cs/DistanceEstimationTracking
Chemical enrichment in groups and clusters
Creators: name: Mernier, François
name: Biffi, Veronica
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: As building blocks of dust, rocky planets, and even complex life, the chemical elements heavier than hydrogen (H) and helium (He) - called "metals" in astronomy - play an essential role in our Universe and its evolution. Up to Fe and Ni, these metals are known to be created by stars and stellar remnants via nuclear fusion and to be ejected into their immediate surroundings to enrich new stellar generations. A spectacular finding, however, is that these processed elements are found even outside stellar systems, in particular in the hot, X-ray atmospheres surrounding early-type galaxies and pervading galaxy clusters and groups. These large-scales structures are thus a remarkable fossil record of the integrated history of the enrichment of our Universe. In this Chapter, we briefly discuss the chemical properties of this intracluster - or intragroup - medium (ICM). After introducing the concept of chemical abundances, and recalling which stellar sources produce which elements, we review the method to derive abundance measurements from observations of the ICM and detail some chemical models implemented in numerical hydrodynamical simulations of cosmic structures. In particular, we explore how synergies between X-ray observations and numerical simulations help us to understand (i) the cosmic epoch at which the bulk of the enrichment occurred, (ii) the physics of these stellar sources responsible for this enrichment, and (iii) the main mechanisms responsible for metal diffusion and mixing outside galaxies.
description: 44 pages, 11 figures. This Chapter will appear in the Section "Galaxy Clusters" (Section Editors: E. Pointecouteau, E. Rasia, A. Simionescu) of the "Handbook of X-ray and Gamma-ray Astrophysics" (Editors in chief: C. Bambi and A. Santangelo)
Relativistic equation of state at subnuclear densities in the Thomas-Fermi approximation
Creators: name: Zhang, Z. W.
name: Shen, H.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Nuclear Theory (nucl-th)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We study the non-uniform nuclear matter using the self-consistent Thomas--Fermi approximation with a relativistic mean-field model. The non-uniform matter is assumed to be composed of a lattice of heavy nuclei surrounded by dripped nucleons. At each temperature $T$, proton fraction $Y_p$, and baryon mass density $ρ_B$, we determine the thermodynamically favored state by minimizing the free energy with respect to the radius of the Wigner--Seitz cell, while the nucleon distribution in the cell can be determined self-consistently in the Thomas--Fermi approximation. A detailed comparison is made between the present results and previous calculations in the Thomas--Fermi approximation with a parameterized nucleon distribution that has been adopted in the widely used Shen EOS.
description: 26 pages, 9 figures
Evidence for a spinon Kondo effect in cobalt atoms on single-layer 1T-TaSe$_2$
Creators: name: Chen, Yi
name: He, Wen-Yu
name: Ruan, Wei
name: Hwang, Jinwoong
name: Tang, Shujie
name: Lee, Ryan L.
name: Wu, Meng
name: Zhu, Tiancong
name: Zhang, Canxun
name: Ryu, Hyejin
name: Wang, Feng
name: Louie, Steven G.
name: Shen, Zhi-Xun
name: Mo, Sung-Kwan
name: Lee, Patrick A.
name: Crommie, Michael F.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Quantum spin liquids (QSLs) are highly entangled, disordered magnetic states that arise in frustrated Mott insulators and host exotic fractional excitations such as spinons and chargons. Despite being charge insulators some QSLs are predicted to exhibit gapless itinerant spinons that yield metallic behavior in the spin channel. We have deposited isolated magnetic atoms onto single-layer (SL) 1T-TaSe$_2$, a gapless QSL candidate, to experimentally probe how itinerant spinons couple to impurity spin centers. Using scanning tunneling spectroscopy we observe the emergence of new, impurity-induced resonance peaks at the 1T-TaSe$_2$ Hubbard band edges when cobalt adatoms are positioned to have maximal spatial overlap with the Hubbard band charge distribution. These resonance peaks disappear when the spatial overlap is reduced or when the magnetic impurities are replaced with non-magnetic impurities. Theoretical simulations using a modified Anderson impurity model integrated with a gapless quantum spin liquid show that these resonance peaks are consistent with a Kondo resonance induced by spinons combined with spinon-chargon binding effects that arise due to QSL gauge-field fluctuations.
Diffusive regimes in a two-dimensional chiral fluid
Creators: name: Reyes, Francisco Vega
name: López-Castaño, Miguel A.
name: Rodríguez-Rivas, Álvaro
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Diffusion is a fundamental aspect of transport processes in biological systems, and thus, in the development of life itself. And yet, the diffusive dynamics of active fluids with directed rotation, known as chiral fluids, has not been analyzed in detail so far. Here, we describe the diffusive regimes of a two-dimensional chiral fluid, composed in this case of a set of identical disk-shaped rotors. We found strong experimental evidence of odd diffusion. This odd diffusion emerges in the form of a two-dimensional tensor with an antisymmetric part. In particular, we show that chiral diffusion is complex, featuring transitions between super, quasi-normal, and sub diffusion, and very slowly aging. Moreover, we show that the diffusion tensor elements, including off-diagonal elements; i.e., odd diffusion coefficient, change sign according to flow vorticity. Therefore, the chiral fluid has a self regulated diffusion, controlled by its vorticity.
description: Accepted in Communications Physics. 8 pages, 4 figures
Mechanics of Tunable Helices and Geometric Frustration in Biomimetic Seashells
Creators: name: Guo, Qiaohang
name: Chen, Zi
name: Li, Wei
name: Dai, Pinqiang
name: Ren, Kun
name: Lin, Junjie
name: Taber, Larry A.
name: Chen, Wenzhe
Publisher: name: arXiv
Year: 2013
Subjects: subject: Mathematical Physics (math-ph)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: Helical structures are ubiquitous in nature and engineering, ranging from DNA molecules to plant tendrils, from sea snail shells to nanoribbons. While the helical shapes in natural and engineered systems often exhibit nearly uniform radius and pitch, helical shell structures with changing radius and pitch, such as seashells and some plant tendrils, adds to the variety of this family of aesthetic beauty. Here we develop a comprehensive theoretical framework for tunable helical morphologies, and report the first biomimetic seashell-like structure resulting from mechanics of geometric frustration. In previous studies, the total potential energy is everywhere minimized when the system achieves equilibrium. In this work, however, the local energy minimization cannot be realized because of the geometric incompatibility, and hence the whole system deforms into a shape with a global energy minimum whereby the energy in each segment may not necessarily be locally optimized. This novel approach can be applied to develop materials and devices of tunable geometries with a range of applications in nano/biotechnology.
Fusing multiple W states simultaneously with a Fredkin gate
Creators: name: Ozaydin, Fatih
name: Bugu, Sinan
name: Yesilyurt, Can
name: Altintas, Azmi Ali
name: Tame, Mark
name: Ozdemir, Sahin Kaya
Publisher: name: arXiv
Year: 2014
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We propose an optical scheme to prepare large-scale entangled networks of W states. The scheme works by simultaneously fusing three polarization-encoded W states of arbitrary size via accessing only one qubit of each W state. It is composed of a Fredkin gate (controlled-swap gate), two fusion gates [as proposed in New J. Phys. 13, 103003 (2011)] and an H-polarized ancilla photon. Starting with three $n$-qubit W states, the scheme prepares a new W state with $3(n-1)$-qubits after postselection if both fusion gates operate successfully, i.e. a four-fold coincidence at the detectors. The proposed scheme reduces the cost of creating arbitrarily large W states considerably when compared to previously reported schemes.
description: 8 pages, 4 figures
A tensor norm approach to quantum compatibility
Creators: name: Bluhm, Andreas
name: Nechita, Ion
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Measurement incompatibility is one of the most striking examples of how quantum physics is different from classical physics. Two measurements are incompatible if they cannot arise via classical post-processing from a third one. A natural way to quantify incompatibility is in terms of noise robustness. In the present article, we review recent results on the maximal noise robustness of incompatible measurements, which have been obtained by the present authors using free spectrahedra, and rederive them using tensor norms. In this way, we make them accessible to a broader audience from quantum information theory and mathematical physics and contribute to the fruitful interactions between Banach space theory and quantum information theory. We also describe incompatibility witnesses using tensor norm and matrix convex set duality, emphasizing the relation between the different notions of witnesses.
description: 18 pages, 1 figure
The Minkowski Billiard Characterization of the EHZ-capacity of Convex Lagrangian Products
Creators: name: Rudolf, Daniel
Publisher: name: arXiv
Year: 2022
Subjects: subject: Dynamical Systems (math.DS)
subject: FOS: Mathematics
subject: 37C83, 37J39, 53D50

description: We rigorously state the connection between the EHZ-capacity of convex Lagrangian products $K\times T\subset\mathbb{R}^n\times\mathbb{R}^n$ and the minimal length of closed $(K,T)$-Minkowski billiard trajectories. This connection was made explicit for the first time by Artstein-Avidan and Ostrover under the assumption of smoothness and strict convexity of both $K$ and $T$. We prove this connection in its full generality, i.e., without requiring any conditions on the convex bodies $K$ and $T$. This prepares the computation of the EHZ-capacity of convex Lagrangian products of two convex polytopes by using discrete computational methods.
description: 22 pages, 5 figures
Verification of Bitcoin Script in Agda using Weakest Preconditions for Access Control
Creators: name: Alhabardi, Fahad F.
name: Beckmann, Arnold
name: Lazar, Bogdan
name: Setzer, Anton
Publisher: name: arXiv
Year: 2022
Subjects: subject: Symbolic Computation (cs.SC)
subject: Cryptography and Security (cs.CR)
subject: Logic in Computer Science (cs.LO)
subject: Social and Information Networks (cs.SI)
subject: FOS: Computer and information sciences

description: This paper contributes to the verification of programs written in Bitcoin's smart contract language SCRIPT in the interactive theorem prover Agda. It focuses on the security property of access control for SCRIPT programs that govern the distribution of Bitcoins. It advocates that weakest preconditions in the context of Hoare triples are the appropriate notion for verifying access control. It aims at obtaining human-readable descriptions of weakest preconditions in order to close the validation gap between user requirements and formal specification of smart contracts. As examples for the proposed approach, the paper focuses on two standard SCRIPT programs that govern the distribution of Bitcoins, Pay to Public Key Hash (P2PKH) and Pay to Multisig (P2MS). The paper introduces an operational semantics of the SCRIPT commands used in P2PKH and P2MS, which is formalised in the Agda proof assistant and reasoned about using Hoare triples. Two methodologies for obtaining human-readable descriptions of weakest preconditions are discussed: (1) a step-by-step approach, which works backwards instruction by instruction through a script, sometimes grouping several instructions together; (2) symbolic execution of the code and translation into a nested case distinction, which allows to read off weakest preconditions as the disjunction of conjunctions of conditions along accepting paths. A syntax for equational reasoning with Hoare Triples is defined in order to formalise those approaches in Agda. Keywords and phrases: Blockchain; Cryptocurrency; Bitcoin; Agda; Verification; Hoare logic; Bitcoin script; P2PKH; P2MS; Access control; Weakest precondition; Predicate transformer semantics; Provable correctness; Symbolic execution; Smart contracts
description: 27 pages
Video Mapping in Audiovisual Performances: Projecting the Club Scene Onto the Urban Space
Creators: name: Watier, Maxime
Publisher: name: Cinergie – Il Cinema e le altre Arti
Year: 2018
Subjects: Audiovisual Performance; Video Mapping; Architecture; Projection; Intermediality

description: This article focuses on the use and evolution of video mapping in audio-visual performances over the last decade. This multimedia technology, used for projecting light or video onto volumes, was quickly adopted by the A/V scene, and was the subject of numerous outdoor shows. Our paper details the multiple functions of this projective technique as a singular type of multimedia production based on mixing live sound and visual materials for an audience, through a process of technological mediation. The search for new visual experiences, through gigantism, relief and depth effects, will take this practice beyond the boundaries of clubs, thus reaching a broader audience.

We will demonstrate through video mapping, how audio-visual performers extend the synesthetic experiments which are at the core of this practice, both spatially and technologically. We then illustrate, by way of example, how these visual artists reshape urban space, most notably by considering buildings’ facades as the original sensory interface between the tactile activity operated by the performer in his work of visualization and sound, with the public who interacts with the audio-visual objects created.
description: Cinergie – Il Cinema e le altre Arti, No 14 (2018)
Global evolution of the magnetic field in a thin disc and its consequences for protoplanetary systems
Creators: name: Guilet, Jerome
name: Ogilvie, Gordon I.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: FOS: Physical sciences

description: The strength and structure of the large-scale magnetic field in protoplanetary discs are still unknown, although they could have important consequences for the dynamics and evolution of the disc. Using a mean-field approach in which we model the effects of turbulence through enhanced diffusion coefficients, we study the time-evolution of the large-scale poloidal magnetic field in a global model of a thin accretion disc, with particular attention to protoplanetary discs. With the transport coefficients usually assumed, the magnetic field strength does not significantly increase radially inwards, leading to a relatively weak magnetic field in the inner part of the disc. We show that with more realistic transport coefficients that take into account the vertical structure of the disc and the back-reaction of the magnetic field on the flow as obtained by Guilet & Ogilvie (2012), the magnetic field can significantly increase radially inwards. The magnetic-field profile adjusts to reach an equilibrium value of the plasma $β$ parameter (the ratio of midplane thermal pressure to magnetic pressure) in the inner part of the disc. This value of $β$ depends strongly on the aspect ratio of the disc and on the turbulent magnetic Prandtl number, and lies in the range $10^4-10^7$ for protoplanetary discs. Such a magnetic field is expected to affect significantly the dynamics of protoplanetary discs by increasing the strength of MHD turbulence and launching an outflow. We discuss the implications of our results for the evolution of protoplanetary discs and for the formation of powerful jets as observed in T-Tauri star systems.
description: 19 pages, 12 figures, accepted for publication in MNRAS
Machine Learning for Encrypted Malicious Traffic Detection: Approaches, Datasets and Comparative Study
Creators: name: Wang, Zihao
name: Fok, Kar-Wai
name: Thing, Vrizlynn L. L.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cryptography and Security (cs.CR)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: As people's demand for personal privacy and data security becomes a priority, encrypted traffic has become mainstream in the cyber world. However, traffic encryption is also shielding malicious and illegal traffic introduced by adversaries, from being detected. This is especially so in the post-COVID-19 environment where malicious traffic encryption is growing rapidly. Common security solutions that rely on plain payload content analysis such as deep packet inspection are rendered useless. Thus, machine learning based approaches have become an important direction for encrypted malicious traffic detection. In this paper, we formulate a universal framework of machine learning based encrypted malicious traffic detection techniques and provided a systematic review. Furthermore, current research adopts different datasets to train their models due to the lack of well-recognized datasets and feature sets. As a result, their model performance cannot be compared and analyzed reliably. Therefore, in this paper, we analyse, process and combine datasets from 5 different sources to generate a comprehensive and fair dataset to aid future research in this field. On this basis, we also implement and compare 10 encrypted malicious traffic detection algorithms. We then discuss challenges and propose future directions of research.
A Fundamental Theorem for Hypersurfaces in Semi-Riemannian Warped Products
Creators: name: Lawn, Marie-Amelie
name: Ortega, Miguel
Publisher: name: arXiv
Year: 2014
Subjects: subject: Differential Geometry (math.DG)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 53C50, 53C40, 53C80, 83C05

description: We give necessary and sufficient conditions for a semi-Riemannian manifold of arbitrary signature to be locally isometrically immersed into certain warped products. Then, we describe a way to use the structure equations of such immersions to construct foliations of marginally trapped surfaces in a four-dimensional Lorentzian spacetimes. We point out that, sometimes, Gauss and Codazzi equations are not sufficient to ensure the existence of a local isometric immersion of a semi-Riemannian manifold as a hypersurface of another manifold. We finally give two low-dimensional examples to illustrate our results.
description: 26 pages
A simulation study of tau neutrino events at the ICAL detector in INO
Creators: name: Senthil, R. Thiru
name: Indumathi, D.
name: Shukla, Prashant
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We present the first detailed simulation study of tau neutrino-induced charged current (CC) events from atmospheric neutrino interactions in the Iron Calorimeter (ICAL) detector at the proposed India-based Neutrino Observatory (INO) laboratory. Since the intrinsic atmospheric neutrino flux at few to 10s of GeV energy comprises only electron and muon neutrinos (and anti-neutrinos) with negligible tau neutrino component, any signature of atmospheric tau neutrinos is a signal for neutrino oscillations. We study the tau leptons produced through these CC interactions via their hadronic decay. These events appear as an excess over the neutral current (NC) background where hadrons are the only observable component. We find that the presence of tau neutrinos in the atmospheric neutrino flux can be demonstrated to nearly $4σ$ confidence with 10 years data; in addition, these events are sensitive to the neutrino oscillation parameters, $\sin^2θ_{23}$ and $\vert Δm_{31}^2 \vert$ (or $\vert Δm_{32}^2 \vert$), in the 2--3 sector. Finally, we show that combining these events with the standard muon analysis which is the core goal of ICAL further improves the precision with which these parameters, especially the octant of $θ_{23}$, can be measured.
description: 27 pages, 13 figures, latex document, revised to include more details on the effect of fluctuations, dependence on exposure time, and inclusion of a discussion of hadron energy systematics. Version accepted in PRD
MPEC 2023-E45 : 2023 EJ
Creators: name: Minor Planet Center Staff
Publisher: name: The Minor Planet Center
Year: 2023
Subjects: subject: Small Solar System bodies
valueUri: http://astrothesaurus.org/uat/1469
subject: 2023 EJ

description: The Minor Planet Electronic Circulars contain information on unusual minor planets, routine data on comets and natural satellites, and occasional editorial announcements.  They are published on behalf of Division F of the International Astronomical Union by the Minor Planet Center, Smithsonian Astrophysical Observatory, Cambridge, MA 02138, U.S.A.
The Construction of the Postsocialist Urban Identity: China’s Reform and Drifting Urban Population
Creators: name: Deng, Huimin
Publisher: name: Cinergie – Il Cinema e le altre Arti
Year: 2018
Subjects: urban drifters; socialist movements; social reform; ideological transformation; spatial movement

description: In the transition from the socialist system to the postsocialist system since 1978, thousands of Chinese urban-to-rural migrant workers and students of socialist movements and urban laid-off workers of socialist state-owned enterprises were no longer safeguarded by Chinese government in terms of political status, job opportunities, welfare, and living standard. Struggling for returning to cities and integrating into the competitory market economy become the living dilemma of the two urban groups respectively. This paper explores the images of those troubled urban figures within both the Chinese Sixth Generation cinema and the Chinese independent documentary. It aims at exposing Chinese urban people’s drifting experience within the postsocialist social context in relation to Chinese modern cinema. The spatial and ideological drifting of troubled urban people in postsocialist China, it shall argue, derives from the transition from the socialist class struggle to the postsocialist economy-oriented reform and from the socialist planned economy to the postsocialist market economy.
description: Cinergie – Il Cinema e le altre Arti, No 14 (2018)
Visualising the Imageless Past: Film and Audio-Visual Media in Archaeological Museums
Creators: name: Haller, Andrea
Publisher: name: Cinergie – Il Cinema e le altre Arti
Year: 2018
Subjects: Film in museums; Media in museums; Prehistory museums; Museums Analysis; Representation of history in museums

description: This paper focuses on the use of film and audio-visual media in an exhibition context, as a means  for mediating the objects of culture on display, which in turn supports the narration of the exhibition. The paper focuses on two German museums, one of archaeology and the other of prehistory, to examine exhibition practices through the different functions of audio-visual media. How does audio-visual media help to visualise the past? How do they contribute to unveil the immaterial side, i.e. the “meaning” and significance of the objects on display? What kind of picture does the synergy between material objects and audio-visual media paint of our ancestors? Moreover, how can audio-visual media help museums to deal with the basic problem of archaeology (and historiography in general) and the representation of history? Finally, in what ways are audio-visual media used to inform the discipline and methods of archaeology, as a process for gaining knowledge?

The analysis will demonstrate how the exhibition spaces of prehistory museums have distinct ways of integrating moving images, thus reflecting the different attitudes they have towards the materiality and mediality of the museum object and, as a consequence, the representation of history in the museum space.
description: Cinergie – Il Cinema e le altre Arti, No 14 (2018)
Quantum fields in curved space-time, semiclassical gravity, quantum gravity phenomenology, and analogue models: Report on session D4 at GR20
Creators: name: Fewster, Christopher J
name: Liberati, Stefano
Publisher: name: arXiv
Year: 2014
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: The talks given in parallel session D4 at the 20th International Conference on General Relativity and Gravitation (Warsaw 2013) are summarized.
description: 15pp. To appear in the GR20 Proceedings issue of General Relativity and Gravitation
Sm-Co-based amorphous alloy films for zero-field operation of transverse thermoelectric generation
Creators: name: Modak, Rajkumar
name: Sakuraba, Yuya
name: Hirai, Takamasa
name: Yagi, Takashi
name: Sepehri-Amin, Hossein
name: Zhou, Weinan
name: Masuda, Hiroto
name: Seki, Takeshi
name: Takanashi, Koki
name: Ohkubo, Tadakatsu
name: Uchida, Ken-ichi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Applied Physics (physics.app-ph)
subject: FOS: Physical sciences

description: Transverse thermoelectric generation using magnetic materials is essential to develop active thermal engineering technologies, for which the improvements of not only the thermoelectric output but also applicability and versatility are required. In this study, using combinatorial material science and lock-in thermography technique, we have systematically investigated the transverse thermoelectric performance of Sm-Co-based alloy films. The high-throughput material investigation revealed the best Sm-Co-based alloys with the large anomalous Nernst effect (ANE) as well as the anomalous Ettingshausen effect (AEE). In addition to ANE/AEE, we discovered unique and superior material properties in these alloys: the amorphous structure, low thermal conductivity, and large in-plane coercivity and remanent magnetization. These properties make it advantageous over conventional materials to realize heat flux sensing applications based on ANE, as our Sm-Co-based films can generate thermoelectric output without an external magnetic field. Importantly, the amorphous nature enables the fabrication of these films on various substrates including flexible sheets, making the large-scale and low-cost manufacturing easier. Our demonstration will provide a pathway to develop flexible transverse thermoelectric devices for smart thermal management.
description: 40 pages in total, 10 main figures, 1 graphical abstract, 3 supplementary figures
Can Self-Ordering Scalar Fields explain the BICEP2 B-mode signal?
Creators: name: Durrer, Ruth
name: Figueroa, Daniel G.
name: Kunz, Martin
Publisher: name: arXiv
Year: 2014
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We show that self-ordering scalar fields (SOSF), i.e. non-topological cosmic defects arising after a global phase transition, cannot explain the B-mode signal recently announced by BICEP2. We compute the full $C_\ell^{B}$ angular power spectrum of B-modes due to the vector and tensor perturbations of SOSF, modeled in the large-N limit of a spontaneous broken global O(N) symmetry. We conclude that the low-$\ell$ multipoles detected by BICEP2 cannot be due mainly to SOSF, since they have the wrong spectrum at low multipoles. As a byproduct we derive the first cosmological constraints on this model, showing that the BICEP2 B-mode polarization data admits at most a 2-3% contribution from SOSF in the temperature anisotropies, similar to (but somewhat tighter than) the recently studied case of cosmic strings.
description: 14 pages, 5 figures
Self-consistent $\textbf{k}\cdot \textbf{p}$ calculations for gated thin layers of 3D Topological Insulators
Creators: name: Baum, Yuval
name: Böttcher, Jan
name: Brüne, Christoph
name: Thienel, Cornelius
name: Molenkamp, Laurens W.
name: Stern, Ady
name: Hankiewicz, Ewelina M.
Publisher: name: arXiv
Year: 2014
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Topological protected surface states are one of the hallmarks of three-dimensional topological insulators. In this work we theoretically analyze the gate-voltage-effects on a quasi-3D layer of HgTe. We find that while the gapless surface states dominate the transport, as an external gate voltage is applied, the existence of bulk charge carriers is likely to occur. We also find that due to screening effects, physical properties that arise from the bottom surface are gate-voltage independent. Finally, we point out the experimental signatures that characterize these effects.
description: 8 pages, 9 figures
Non-Fermi liquid behavior of large N_B quantum critical metals
Creators: name: Fitzpatrick, A. Liam
name: Kachru, Shamit
name: Kaplan, Jared
name: Raghu, S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The problem of continuous quantum phase transitions in metals involves critical bosons coupled to a Fermi surface. We solve the theory in the limit of a large number, N_B, of bosonic flavors, where the bosons transform in the adjoint representation, while the fermions are in the fundamental representation of a global SU(N_B) flavor symmetry group. The leading large N_B solution corresponds to a non-Fermi liquid coupled to Wilson-Fisher bosons. In a certain energy range, the fermion velocity vanishes - resulting in the destruction of the Fermi surface. Subleading 1/N_B corrections correspond to a qualitatively different form of Landau damping of the bosonic critical fluctuations. We discuss the model in d=3-epsilon but because of the additional control afforded by large N_B, our results are valid down to d=2. In the limit epsilon << 1, the large N_B solution is consistent with the RG analysis of Ref. 1.
description: 16+5 pages, 5 figures
Color confinement, chiral symmetry breaking, and catalytic effect induced by monopole and instanton creations
Creators: name: Hasegawa, Masayasu
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Our research reveals the relations among monopoles, color confinement, instantons, and chiral symmetry breaking which experiments can detect, by numerical calculations of lattice gauge theory. We first add a monopole and an anti-monopole varying their magnetic charges to the gauge field configurations in the quenched approximation of quantum chromodynamics (QCD), by applying the monopole creation operator and investigate the effects of the added monopoles and anti-monopoles on color confinement. Second, we reveal the quantitative relations among instantons, anti-instantons, and observables using the eigenvalues and eigenvectors of the overlap Dirac operator, which are calculated using the normal configurations and the configurations with the additional monopoles and anti-monopoles. Finally, we ascertain the outcomes by comparing them with the predictions. We have already discovered the catalytic effect: the decay width of the charged pion becomes wider and its lifetime becomes shorter than the experimental outcomes by increasing the number density of instantons and anti-instantons. However, the outcomes in the previous study were obtained using one lattice volume and lattice spacing. In this research, we improve the previous study using a variety of configurations of different lattice volumes and values of the lattice spacing from low to finite temperatures. The main purposes of this study are to inspect the influences of the finite lattice volume and discretization on the observables and quantitative relations that we have obtained in our previous research and to acquire the interpolated results at the continuum limit.
description: 36 pages, 21 figures, and 33 tables