cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
[Document de référence] Wolfgang Schäuble. Non-paper for paving the way towards a Stability Union, October 2017. Revue ECU/EURO, N°52 (2018)
Creators: name: Schäuble, Wolfgang
Publisher: name: RESuME
Year: 2018
Subjects: subject: Economic and Monetary Union
subject: Union économique et monétaire
subject: EMU Reform
subject: Réforme de l'UEM
subject: Fiscal Policy
subject: Politique budgétaire
subject: Europe's Banking Union
subject: Union bancaire européenne
subject: European Stability Mechanism
subject: Mécanisme européen de stabilité
subject: Wolfgang Schäuble

description: While he was offered mementos ranging from a €100 bill bearing his face (a dubious act of monetary financing from Slovakia's Peter Kazimir) to a 2004 bottle of Bordeaux (from France's Bruno Le Maire), Mr Schäuble's offering — titled “Paving the way towards a Stability Union” — was something of a party/Schäuble's parting gift highlights French-German split
Doc revealed by Il Corriere della Sierra.
Majorana bound states in the presence of the half-smeared potential
Creators: name: Basak, Surajit
name: Ptok, Andrzej
Publisher: name: arXiv
Year: 2022
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The Majorana bound state can be realized in one dimensional chain, in form of two well localized and separated states at both ends of the chain. In this paper, we discuss the case when the potential is smeared at one end of the system. In our investigation, we assume the smearing in form of a quadratic function of position. We show that the smearing potential lead to the emergence of extra in-gap states, and effectively decrease the local gap (around the smeared potential). The Majorana states are still preserved in the system, however, their localization depend on the smearing. Moreover, the symmetric localization of the Majorana states from both side of the system is no longer preserved in the presence of the smearing potential.
description: 6 pages, 4 figures
Termination dependence of the surface states in Pb$_{2}$Pd
Creators: name: Basak, Surajit
name: Ptok, Andrzej
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Topological properties of systems lead to the emergence of surface states which can be observed experimentally within the angle-resolved photoemission spectroscopy (ARPES) measurements. Recently, the topological properties of Pb$_{2}$Pd were reported. In this paper, we discuss the role of the surface termination on the realized surface states. We discuss the termination dependence of the surface state for (001) and (110) surface. We demonstrate that the Pd terminated (001) surface allow realization of the Dirac cone-like surface state. In the case (110) we observe well visible surface states with parabolic-like dispersion relation in close vicinity of the Fermi level.
description: 6 pages, 5 figures
Subluminality of relativistic quantum tunneling
Creators: name: Gavassino, Lorenzo
name: Disconzi, Marcelo M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We prove that the classical Dirac equation in the presence of an external (nondynamical) electromagnetic field is a relativistically causal theory. As a corollary, we show that it is impossible to use quantum tunneling to transmit particles or information faster than light. When an electron tunnels through a barrier, it is bound to remain within its future light cone. In conclusion, the relativistic quantum tunneling (if modeled using the Dirac equation) is an entirely subluminal process, and it is not instantaneous.
description: 14 pages, 6 figures, published on PRA (see https://doi.org/10.1103/PhysRevA.107.032209)
Generalized Coherent States, Reproducing Kernels, and Quantum Support Vector Machines
Creators: name: Chatterjee, Rupak
name: Yu, Ting
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: The support vector machine (SVM) is a popular machine learning classification method which produces a nonlinear decision boundary in a feature space by constructing linear boundaries in a transformed Hilbert space. It is well known that these algorithms when executed on a classical computer do not scale well with the size of the feature space both in terms of data points and dimensionality. One of the most significant limitations of classical algorithms using non-linear kernels is that the kernel function has to be evaluated for all pairs of input feature vectors which themselves may be of substantially high dimension. This can lead to computationally excessive times during training and during the prediction process for a new data point. Here, we propose using both canonical and generalized coherent states to rapidly calculate specific nonlinear kernel functions. The key link will be the reproducing kernel Hilbert space (RKHS) property for SVMs that naturally arise from canonical and generalized coherent states. Specifically, we discuss the fast evaluation of radial kernels through a positive operator valued measure (POVM) on a quantum optical system based on canonical coherent states. A similar procedure may also lead to fast calculations of kernels not usually used in classical algorithms such as those arising from generalized coherent states.
description: 9 pages, 3 figures
Preemptive Scheduling of EV Charging for Providing Demand Response Services
Creators: name: Shao, Shiping
name: Harirchi, Farshad
name: Dave, Devang
name: Gupta, Abhishek
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: We develop a new algorithm for scheduling the charging process of a large number of electric vehicles (EVs) over a finite horizon. We assume that EVs arrive at the charging stations with different charge levels and different flexibility windows. The arrival process is assumed to have a known distribution and that the charging process of EVs can be preemptive. We pose the scheduling problem as a dynamic program with constraints. We show that the resulting formulation leads to a monotone dynamic program with Lipschitz continuous value functions that are robust against perturbation of system parameters. We propose a simulation based fitted value iteration algorithm to determine the value function approximately, and derive the sample complexity for computing the approximately optimal solution.
description: 21 pages, submitted to SEGAN
MorphoNoC: Exploring the Design Space of a Configurable Hybrid NoC using Nanophotonics
Creators: name: Narayana, Vikram K.
name: Sun, Shuai
name: Badawy, Abdel-Hameed A.
name: Sorger, Volker J.
name: El-Ghazawi, Tarek
Publisher: name: arXiv
Year: 2017
Subjects: subject: Other Computer Science (cs.OH)
subject: Emerging Technologies (cs.ET)
subject: FOS: Computer and information sciences

description: As diminishing feature sizes drive down the energy for computations, the power budget for on-chip communication is steadily rising. Furthermore, the increasing number of cores is placing a huge performance burden on the network-on-chip (NoC) infrastructure. While NoCs are designed as regular architectures that allow scaling to hundreds of cores, the lack of a flexible topology gives rise to higher latencies, lower throughput, and increased energy costs. In this paper, we explore MorphoNoCs - scalable, configurable, hybrid NoCs obtained by extending regular electrical networks with configurable nanophotonic links. In order to design MorphoNoCs, we first carry out a detailed study of the design space for Multi-Write Multi-Read (MWMR) nanophotonics links. After identifying optimum design points, we then discuss the router architecture for deploying them in hybrid electronic-photonic NoCs. We then study explore the design space at the network level, by varying the waveguide lengths and the number of hybrid routers. This affords us to carry out energy-latency trade-offs. For our evaluations, we adopt traces from synthetic benchmarks as well as the NAS Parallel Benchmark suite. Our results indicate that MorphoNoCs can achieve latency improvements of up to 3.0x or energy improvements of up to 1.37x over the base electronic network.
description: 14 pages, 15 figures
Exploiting Temporal Structures of Cyclostationary Signals for Data-Driven Single-Channel Source Separation
Creators: name: Lee, Gary C. F.
name: Weiss, Amir
name: Lancho, Alejandro
name: Tang, Jennifer
name: Bu, Yuheng
name: Polyanskiy, Yury
name: Wornell, Gregory W.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Signal Processing (eess.SP)
subject: Artificial Intelligence (cs.AI)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: We study the problem of single-channel source separation (SCSS), and focus on cyclostationary signals, which are particularly suitable in a variety of application domains. Unlike classical SCSS approaches, we consider a setting where only examples of the sources are available rather than their models, inspiring a data-driven approach. For source models with underlying cyclostationary Gaussian constituents, we establish a lower bound on the attainable mean squared error (MSE) for any separation method, model-based or data-driven. Our analysis further reveals the operation for optimal separation and the associated implementation challenges. As a computationally attractive alternative, we propose a deep learning approach using a U-Net architecture, which is competitive with the minimum MSE estimator. We demonstrate in simulation that, with suitable domain-informed architectural choices, our U-Net method can approach the optimal performance with substantially reduced computational burden.
Tau energy loss and ultrahigh energy skimming tau neutrinos
Creators: name: Jeong, Yu Seon
name: Luu, Minh Vu
name: Reno, Mary Hall
name: Sarcevic, Ina
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We consider propagation of high energy earth-skimming taus produced in interactions of astrophysical tau neutrinos. For astrophysical tau neutrinos we take generic power-law flux, $E^{-2}$ and the cosmogenic flux initiated by the protons. We calculate tau energy loss in several approaches, such as dipole models and the phenomenological approach in which parameterization of the $F_2$ is used. We evaluate the tau neutrino charged-current cross section using the same approaches for consistency. We find that uncertainty in the neutrino cross section and in the tau energy loss partially compensate giving very small theoretical uncertainty in the emerging tau flux for distances ranging from $2$ km to $100$ km and for the energy range between $10^6$ GeV and $10^{11}$ GeV, focusing on energies above $10^8$ GeV. When we consider uncertainties in the neutrino cross section, inelasticity in neutrino interactions and the tau energy loss, which are not correlated, i.e. they are not all calculated in the same approach, theoretical uncertainty ranges from about $30\%$ and $60 \%$ at $10^8$ GeV to about factors of 3.3 and 3.8 at $10^{11}$ GeV for the $E^{-2}$ flux and the cosmogenic flux, respectively, for the distance of 10 km rock. The spread in predictions significantly increases for much larger distances, e.g., $\sim 1,000$ km. Most of the uncertainty comes from the treatment of photonuclear interactions of the tau in transit through large distances. We also consider Monte Carlo calculation of the tau propagation and we find that the result for the emerging tau flux is in agreement with the result obtained using analytic approach. Our results are relevant to several experiments that are looking for skimming astrophysical taus, such as the Pierre Auger Observatory, HAWC and Ashra. We evaluate the aperture for the Auger and discuss briefly application to the the other two experiments.
description: 21 pages and 20 figures
Verification-Preserving Inlining in Automatic Separation Logic Verifiers (extended version)
Creators: name: Dardinier, Thibault
name: Parthasarathy, Gaurav
name: Müller, Peter
Publisher: name: arXiv
Year: 2022
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: Bounded verification has proved useful to detect bugs and to increase confidence in the correctness of a program. In contrast to unbounded verification, reasoning about calls via (bounded) inlining and about loops via (bounded) unrolling does not require method specifications and loop invariants and, therefore, reduces the annotation overhead to the bare minimum, namely specifications of the properties to be verified. For verifiers based on traditional program logics, verification is preserved by inlining (and unrolling): successful unbounded verification of a program w.r.t. some annotation implies successful verification of the inlined program. That is, any error detected in the inlined program reveals a true error in the original program. However, this essential property might not hold for automatic separation logic verifiers such as Caper, GRASShopper, RefinedC, Steel, VeriFast, and verifiers based on Viper. In this setting, inlining generally changes the resources owned by method executions, which may affect automatic proof search algorithms and introduce spurious errors. In this paper, we present the first technique for verification-preserving inlining in automatic separation logic verifiers. We identify a semantic condition on programs and prove in Isabelle/HOL that it ensures verification-preserving inlining for state-of-the-art automatic separation logic verifiers. We also prove a dual result: successful verification of the inlined program ensures that there are method and loop annotations that enable the verification of the original program for bounded executions. To check our semantic condition automatically, we present two approximations that can be checked syntactically and with a program verifier, respectively. We implement these checks in Viper and demonstrate that they are effective for non-trivial examples from different verifiers.
title: Mathematical mechanics of one-dimensional filaments in three-dimensional space
Creators: name: Hofer, Jacob S.
Publisher: name: Colorado School of Mines Repository
Year: 2022

description:  one-dimensional filament is a useful mathematical object for modeling a variety of physical phenomena such as vortex filaments. Through a description of the filament using the tangent, normal, and binormal vectors, we get a more meaningful description of the curve in terms of curvature and torsion. Hasimoto's transformation defines a mapping between a kinematic evolution of a space curve and nonlinear scalar equations evolving its intrinsic curve geometry. Through this transformation, the problem of understanding the time evolution of curves can be greatly simplified, yielding useful equations which arise in other areas of nonlinear physics. In our work, we generalize this transformation on arbitrary flows and test against several existing kinematic flows. We consider the time dynamics of length and bending energy to see that binormal flows are generally length-preserving, and bending energy is fragile and unlikely to be conserved in the general case. By describing a space curve in terms of curve geometry, we can perform a transformation that yields a useful description of the time evolution of the curve. Through a generalization of this transformation, we can better understand how the kinematic equation dictates the behavior of the curve, and how this relates to the modeling of physical phenomena.
Chiral topological excitons in the monolayer transition metal dichalcogenides
Creators: name: Gong, Z. R.
name: Luo, W. Z.
name: Jiang, Z. F.
name: Fu, H. C.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We theoretically investigate the chiral topological excitons emerging in the monolayer transition metal dichalcogenides, where a bulk energy gap of valley excitons is opened up by a position dependent external magnetic field. We find two emerging chiral topological nontrivial excitons states, which exactly connects to the bulk topological properties, i.e., Chern number =2. The dependences of the spectrum of the chiral topological excitons on the width of the magnetic field domain wall as well as the magnetic filed strength are numerically revealed. The chiral topological valley excitons are not only important to the excitonic transport due to prevention of the backscattering, but also give rise to the quantum coherent control in the optoelectronic applications.
description: 9 pages, 3 figures
Electrical detection of hyperbolic phonon-polaritons in heterostructures of graphene and boron nitride
Creators: name: Woessner, Achim
name: Parret, Romain
name: Davydovskaya, Diana
name: Gao, Yuanda
name: Wu, Jhih-Sheng
name: Lundeberg, Mark B.
name: Nanot, Sébastien
name: Alonso-González, Pablo
name: Watanabe, Kenji
name: Taniguchi, Takashi
name: Hillenbrand, Rainer
name: Fogler, Michael M.
name: Hone, James
name: Koppens, Frank H. L.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Applied Physics (physics.app-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Light properties in the mid-infrared can be controlled at a deep subwavelength scale using hyperbolic phonons-polaritons (HPPs) of hexagonal boron nitride (h-BN). While propagating as waveguided modes HPPs can concentrate the electric field in a chosen nano-volume. Such a behavior is at the heart of many applications including subdiffraction imaging and sensing. Here, we employ HPPs in heterostructures of h-BN and graphene as new nano-optoelectronic platform by uniting the benefits of efficient hot-carrier photoconversion in graphene and the hyperbolic nature of h-BN. We demonstrate electrical detection of HPPs by guiding them towards a graphene pn-junction. We shine a laser beam onto a gap in metal gates underneath the heterostructure, where the light is converted into HPPs. The HPPs then propagate as confined rays heating up the graphene leading to a strong photocurrent. This concept is exploited to boost the external responsivity of mid-infrared photodetectors, overcoming the limitation of graphene pn-junction detectors due to their small active area and weak absorption. Moreover this type of detector exhibits tunable frequency selectivity due to the HPPs, which combined with its high responsivity paves the way for efficient high-resolution mid-infrared imaging.
Extending the symmetry of the massless Klein-Gordon equation under the general disformal transformation
Creators: name: Alinea, Allan L.
name: Chua, Mark Ruel D.
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: The Klein-Gordon equation, one of the most fundamental equations in field theory, is known to be not invariant under conformal transformation. However, its massless limit exhibits symmetry under Bekenstein's disformal transformation, subject to some conditions on the disformal part of the metric variation. In this study, we explore the symmetry of the Klein-Gordon equation under the general disformal transformation encompassing that of Bekenstein and a hierarchy of `sub-generalisations' explored in the literature (within the context of inflationary cosmology and scalar-tensor theories). We find that the symmetry in the massless limit can be extended under this generalisation provided that the disformal factors takes a special form in relation to the conformal factor. Upon settling the effective extension of symmetry, we investigate the invertibility of the general disformal transformation to avoid propagating non-physical degrees of freedom upon changing the metric. We derive the inverse transformation and the accompanying restrictions that make this inverse possible.
description: 14 pages, accepted for publication in International Journal of Modern Physics A, deleted some unimportant details, clarified that the `orthogonality condition' does not make the field overdetermined, rewritten parts for clarity
Dust-Deficient Palomar-Green Quasars and the Diversity of AGN Intrinsic IR Emission
Creators: name: Lyu, Jianwei
name: Rieke, G. H.
name: Shi, Yong
Publisher: name: arXiv
Year: 2016
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: To elucidate the intrinsic broadband infrared (IR) emission properties of active galactic nuclei (AGNs), we analyze the spectral energy distributions (SEDs) of 87 z<0.5 Palomar-Green (PG) quasars. While the Elvis AGN template with a moderate far-IR correction can reasonably match the SEDs of the AGN components in ~60% of the sample (and is superior to alternatives such as that by Assef), it fails on two quasar populations: 1) hot-dust-deficient (HDD) quasars that show very weak emission thoroughly from the near-IR to the far-IR, and 2) warm-dust-deficient (WDD) quasars that have similar hot dust emission as normal quasars but are relatively faint in the mid- and far-IR. After building composite AGN templates for these dust-deficient quasars, we successfully fit the 0.3-500 μm SEDs of the PG sample with the appropriate AGN template, an infrared template of a star-forming galaxy, and a host galaxy stellar template. 20 HDD and 12 WDD quasars are identified from the SED decomposition, including seven ambiguous cases. Compared with normal quasars, the HDD quasars have AGN with relatively low Eddington ratios and the fraction of WDD quasars increases with AGN luminosity. Moreover, both the HDD and WDD quasar populations show relatively stronger mid-IR silicate emission. Virtually identical SED properties are also found in some quasars from z = 0.5 to 6. We propose a conceptual model to demonstrate that the observed dust deficiency of quasars can result from a change of structures of the circumnuclear tori that can occur at any cosmic epoch.
description: minor corrections to match the published version
$T_5$ configurations and hyperbolic systems
Creators: name: Johansson, Carl Johan Peter
name: Tione, Riccardo
Publisher: name: arXiv
Year: 2022
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35D30, 35L40, 35L65

description: In this paper we study the rank-one convex hull of a differential inclusion associated to entropy solutions of a hyperbolic system of conservation laws. This was introduced in Section 7 of [Kirchheim, Müller, Šverák, 2003] and many of its properties have already been shown in [Lorent, Peng, 2019]-[Lorent, Peng, 2020]. In particular, in [Lorent, Peng 2020] it is shown that the differential inclusion does not contain any $T_4$ configurations. Here we continue that study by showing that the differential inclusion does not contain $T_5$ configurations.
description: Author's Accepted Manuscript
Diverse Title Generation for Stack Overflow Posts with Multiple Sampling Enhanced Transformer
Creators: name: Zhang, Fengji
name: Liu, Jin
name: Wan, Yao
name: Yu, Xiao
name: Liu, Xiao
name: Keung, Jacky
Publisher: name: arXiv
Year: 2022
Subjects: subject: Software Engineering (cs.SE)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Stack Overflow is one of the most popular programming communities where developers can seek help for their encountered problems. Nevertheless, if inexperienced developers fail to describe their problems clearly, it is hard for them to attract sufficient attention and get the anticipated answers. We propose M$_3$NSCT5, a novel approach to automatically generate multiple post titles from the given code snippets. Developers may use the generated titles to find closely related posts and complete their problem descriptions. M$_3$NSCT5 employs the CodeT5 backbone, which is a pre-trained Transformer model having an excellent language understanding and generation ability. To alleviate the ambiguity issue that the same code snippets could be aligned with different titles under varying contexts, we propose the maximal marginal multiple nucleus sampling strategy to generate multiple high-quality and diverse title candidates at a time for the developers to choose from. We build a large-scale dataset with 890,000 question posts covering eight programming languages to validate the effectiveness of M$_3$NSCT5. The automatic evaluation results on the BLEU and ROUGE metrics demonstrate the superiority of M$_3$NSCT5 over six state-of-the-art baseline models. Moreover, a human evaluation with trustworthy results also demonstrates the great potential of our approach for real-world application.
description: under review
Shape-phase transitions in odd-mass $γ$-soft nuclei with mass $A\approx 130$
Creators: name: Nomura, K.
name: Nikšić, T.
name: Vretenar, D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: Quantum phase transitions between competing equilibrium shapes of nuclei with an odd number of nucleons are explored using a microscopic framework of nuclear energy density functionals and a particle-boson core coupling model. The boson Hamiltonian for the even-even core nucleus, as well as the spherical single-particle energies and occupation probabilities of unpaired nucleons, are completely determined by a constrained self-consistent mean-field calculation for a specific choice of the energy density functional and pairing interaction. Only the strength parameters of the particle-core coupling have to be adjusted to reproduce a few empirical low-energy spectroscopic properties of the corresponding odd-mass system. The model is applied to the odd-A Ba, Xe, La and Cs isotopes with mass $A\approx 130$, for which the corresponding even-even Ba and Xe nuclei present a typical case of $γ$-soft nuclear potential. The theoretical results reproduce the experimental low-energy excitation spectra and electromagnetic properties, and confirm that a phase transition between nearly spherical and $γ$-soft nuclear shapes occurs also in the odd-A systems.
description: 13 pages, 15 figures, 9 tables
Adiabatic Index in Fluid Models of Collisionless Black Hole Accretion
Creators: name: Gammie, Charles F.
Publisher: name: arXiv
Year: 2025
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: Models of highly sub-Eddington accretion onto black holes commonly use a single fluid model for the collisionless, near-horizon plasma. These models must specify an equation of state. It is common to use an ideal gas with $p = (γ- 1) u$ and $γ= 4/3, 13/9,$ or $5/3$, but these produce significantly different outcomes. We discuss the origins of this discrepancy and the assumptions underlying the single fluid model. The main result of this investigation is that under conditions relevant to low luminosity black hole accretion the best choice of single fluid adiabatic index is close to but slightly less than $5/3$. Along the way we provide a simple equilibrium model for the relation between the ion-to-electron dissipation ratio and the ion to electron temperature ratio and explore the implications for electron temperature fluctuations in Event Horizon Telescope sources.
description: 8 pages, accepted to ApJ
title: Pairwise entanglement networks as a probe into non-equilibirum quantum dynamics
Creators: name: Barton, Brandon A.
Publisher: name: Colorado School of Mines Repository
Year: 2022

description: Following a sudden change of system parameters known as a quantum quench, the state of a quantum system can exhibit out-of-equilibrium dynamics. When the quench is across a critical point, a dynamical phase transition can occur, indicated by non-analytic behavior in a quantity known as Loschmidt echo. However, measuring the Loschmidt echo requires measurement of the entire quantum state, which is experimentally challenging, even for a moderate system size of a few tens of quantum particles. To address the challenge of detecting dynamical phase transitions, we investigate the possibility of using only information from two-body reduced states of a quantum many-body system for identifying dynamical phase transitions. These two-body reduced states allow us to calculate a network of different pairwise entanglement measures, including connected correlations, concurrence, and mutual information. As the measurement of all two-body reduced states only requires resources quadratic in system size, obtaining pairwise networks of these entanglement measures is experimentally practical. Upon attaining the pairwise networks, we directly examine the weighted adjacency matrices using network science and spectral graph analysis. Our results show that concurrence, an entanglement monotone, oscillates in phase with the rate function. As an example of our procedure, we consider a long-range transverse field Ising model with power-law interactions in the coupling strength. We further show that our methods may provide a considerably more efficient method for probing dynamical phase transitions in a large quantum many-body system. This work also paves the way for characterizing the role of pairwise entanglement in identifying critical phenomena.
Bayesian Optimization-based Combinatorial Assignment
Creators: name: Weissteiner, Jakob
name: Heiss, Jakob
name: Siems, Julien
name: Seuken, Sven
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Computer Science and Game Theory (cs.GT)
subject: Multiagent Systems (cs.MA)
subject: FOS: Computer and information sciences

description: We study the combinatorial assignment domain, which includes combinatorial auctions and course allocation. The main challenge in this domain is that the bundle space grows exponentially in the number of items. To address this, several papers have recently proposed machine learning-based preference elicitation algorithms that aim to elicit only the most important information from agents. However, the main shortcoming of this prior work is that it does not model a mechanism's uncertainty over values for not yet elicited bundles. In this paper, we address this shortcoming by presenting a Bayesian optimization-based combinatorial assignment (BOCA) mechanism. Our key technical contribution is to integrate a method for capturing model uncertainty into an iterative combinatorial auction mechanism. Concretely, we design a new method for estimating an upper uncertainty bound that can be used to define an acquisition function to determine the next query to the agents. This enables the mechanism to properly explore (and not just exploit) the bundle space during its preference elicitation phase. We run computational experiments in several spectrum auction domains to evaluate BOCA's performance. Our results show that BOCA achieves higher allocative efficiency than state-of-the-art approaches.
Udviklingsorienteret undervisningsevaluering
Creators: name: Nielsen, Birgitte Lund
name: Lund, Jens Hansen
Publisher: name: CEPRA-striben
Year: 2019

description: I artiklen deles erfaringer fra et projekt, hvor nye evalueringstilgange på tre såkaldte kompetenceløft-hold for lærere er afprøvet. Målet har været en pædagogisk udviklende og meningsfuld evalueringsproces med anvendelse og diskussion på holdene, snarere end den hidtidige rituelle slutevaluering med meget lave svarprocenter. Inspiration er hentet i udviklingsorienteret evaluering med anerkendelsen af den komplekse kontekst, karakteriseret ved non-linearitet, emergens og kontingens. De deltagende lærere på tre undervisningshold fremhævede særligt de udbytterige drøftelser, at dialog om fagpersonlig udvikling er blevet stilladseret, og at de er blevet inddraget i dialog om evalueringsdesign.
description: CEPRA-striben, Nr. 25 (2019): Åben pædagogik og evaluering
Nonfillable Legendrian knots in the 3-sphere
Creators: name: Etgü, Tolga
Publisher: name: arXiv
Year: 2017
Subjects: subject: Symplectic Geometry (math.SG)
subject: Geometric Topology (math.GT)
subject: FOS: Mathematics

description: If a Legendrian knot $Λ$ in the standard contact 3-sphere bounds an orientable exact Lagrangian surface $Σ$ in the standard symplectic 4-ball, then the genus of $Σ$ is equal to the slice genus of (the smooth knot underlying) $Λ$, the sum of the Thurston-Bennequin number of L and the Euler characteristic of $Σ$ is zero as well as the rotation number of $Λ$, and moreover, the linearized contact homology of $Λ$ with respect to the augmentation induced by $Σ$ is isomorphic to the (singular) homology of $Σ$. It was asked in arXiv:1212.1519 whether the converse of this statement is true. We give a negative answer to this question by providing a family of Legendrian knots with augmentations not induced by any exact Lagrangian filling although the associated linearized contact homology is isomorphic to the homology of the smooth surface of minimal genus in the 4-ball bounding the knot.
description: 10 pages, 2 figures; v2: added Lemma 4
Effective field theory of an anomalous Hall metal from interband quantum fluctuations
Creators: name: Chua, Victor
name: Assawasunthonnet, Wathid
name: Fradkin, Eduardo
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: We construct an effective field theory, a two-dimensional two-component metallic system described by a model with two Fermi surfaces ("pockets"). This model describes a translationally invariant metallic system with two types of fermions, each with its own Fermi surface, with forward scattering interactions. This model, in addition to the $O(2)$ rotational invariance, has a $U(1) \times U(1)$ symmetry of separate charge conservation for each Fermi surface. For sufficiently attractive interactions in the $d$-wave (quadrupolar) channel this model has an interesting phase diagram that includes a spontaneously generated anomalous Hall metal phase. We derive the Landau-Ginzburg effective action of quadrupolar order parameter fields which enjoys an $O(2)\times U(1)$ global symmetry associated to spatial isotropy and the internal $U(1)$ relative phase symmetries respectively. We show that the order parameter theory is dynamically local with a dynamical scaling of $z=2$ and perform a one-loop renormalization group analysis of the Landau-Ginzburg theory. The electronic liquid crystal phases that result from spontaneous symmetry breaking are studied and we show the presence of Landau damped Nambu-Goldstone modes at low momenta that is a signature of non-Fermi liquid behavior. Electromagnetic linear response is also analyzed in both the normal and symmetry broken phases from the point of view of the order parameter theory. The nature of the coupling of electromagnetism to the order parameter fields in the normal phase is non-minimal and decidedly contains a precursor to the anomalous Hall response in the form of a order-parameter-dependent Chern-Simons term in the effective action.
description: 31 pages, 12 figures
Accurate Direct Measurements of Far-Field Thermal Infrared Emission and its Dynamics
Creators: name: Liu, Xiu
name: Salihoglu, Hakan
name: Luo, Xiao
name: Yun, Hyeong Seok
name: Jing, Lin
name: Yu, Bowen
name: Shen, Sheng
Publisher: name: arXiv
Year: 2022
Subjects: subject: Instrumentation and Detectors (physics.ins-det)
subject: Optics (physics.optics)
subject: FOS: Physical sciences

description: Accurate direct measurements of far-field thermal infrared emission become increasingly important because conventional methods, relying on indirect assessments, such as reflectance/transmittance, are inaccurate or even unfeasible to characterize state-of-art devices with novel spectra, directionalities, and polarizations. The direct collection of the far-field emission from these tiny devices is also challenging because of their shrinking footprints and uncontrollable radiation noises from their surroundings. Here, we demonstrate a microscopic lock-in FTIR system that realizes significant improvement in signal-to-noise ratio (SNR) by combining a microscope and a lock-in amplifier with an FTIR. The lock-in FTIR is ultrasensitive, with a specific detectivity 10^6 times higher than commercial ones, to overcome the optical loss and background noise during the emission light collection. Based on an analytical model of the signal detection process, we also explore the combination of modulated Joule heating and global heating to fulfill the potential of our system for noise reduction. Our findings show that, compared to previous studies, more than 3 times lower temperatures are sufficient to generate a measurable signal. Under a heating temperature of around 125 °C, we can achieve an SNR of about 23.7, which is far above the true-signal-threshold (SNR of about 3.0). Furthermore, the system can respond fast enough (up to 175kHz) to record spectral-resolved dynamics of microdevices in the frequency domain. The measurable frequency range can be extended up to MHz or even GHz level by a high-speed circuit model. We believe the system together with the analytical signal processing can be beneficial for next-generation thermal infrared material and device exploration, boosting the applications in lighting, sensing, imaging, and energy harvesting on a small scale.
description: 19 pages, 4 figures
A String Deformation of the Parke-Taylor Factor
Creators: name: Mizera, Sebastian
name: Zhang, Guojun
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: Scattering amplitudes in a range of quantum field theories can be computed using the Cachazo-He-Yuan (CHY) formalism. In theories with colour ordering, the key ingredient is the so-called Parke-Taylor factor. In this note we give a fully $\text{SL}(2,\mathbb{C})$-covariant definition and study the properties of a new integrand called the string Parke-Taylor factor. It has an $α'$ expansion whose leading coefficient is the field-theoretic Parke-Taylor factor. Its main application is that it leads to a CHY formulation of open string tree-level amplitudes. In fact, the definition of the string Parke-Taylor factor was motivated by trying to extend the compact formula for the first $α'$ correction found by He and Zhang, while the main ingredient in its definition is a determinant of a matrix introduced in the context of string theory by Stieberger and Taylor.
description: 12+10 pages
On mechanical waves and Doppler shifts from moving boundaries
Creators: name: Christov, Ivan C.
name: Christov, C. I.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 35L05, 35C20, 78M35

description: We investigate the propagation of infinitesimal harmonic mechanical waves emitted from a boundary with variable velocity and arriving at a stationary observer. In the classical Doppler effect, $X_\mathrm{s}(t) = vt$ is the location of the source with constant velocity $v$. In the present work, however, we consider a source co-located with a moving boundary $x=X_\mathrm{s}(t)$, where $X_\mathrm{s}(t)$ can have an arbitrary functional form. For "slowly moving" boundaries (\textit{i.e.}, ones for which the timescale set by the mechanical motion is large in comparison to the inverse of the frequency of the emitted wave), we present a multiple-scale asymptotic analysis of the moving-boundary problem for the linear wave equation. We obtain a closed-form leading-order (with respect to the latter small parameter) solution and show that the variable velocity of the boundary results not only in frequency modulation but also in amplitude modulation of the received signal. Consequently, our results extending the applicability of two basic tenets of the theory of a moving source on a stationary domain, specifically that (a) $\dot X_\mathrm{s}$ for non-uniform boundary motion can be inserted in place of the constant velocity $v$ in the classical Doppler formula and (b) that the non-uniform boundary motion introduces variability in the amplitude of the wave. The specific examples of decelerating and oscillatory boundary motion are worked out and illustrated.
description: 14 pages, 4 figures, Wiley journal style; accepted for publication in Mathematical Methods in the Applied Sciences; v2 corrects typographical errors
Effects of QCD Equation of State on the Stochastic Gravitational Wave Background
Creators: name: Anand, Sampurn
name: Dey, Ujjal Kumar
name: Mohanty, Subhendra
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Cosmological phase transitions can be a source of Stochastic Gravitational Wave (SGW) background. Apart from the dynamics of the phase transition, the characteristic frequency and the fractional energy density $Ω_{\rm gw}$ of the SGW depends upon the temperature of the transition. In this article, we compute the SGW spectrum in the light of QCD equation of state provided by the lattice results. We find that the inclusion of trace anomaly from lattice QCD, enhances the SGW signal generated during QCD phase transition by $\sim 50\%$ and the peak frequency of the QCD era SGW are shifted higher by $\sim 25\%$ as compared to the earlier estimates without trace anomaly. This result is extremely significant for testing the phase transition dynamics near QCD epoch.
description: 10 pages, 2 figures; minor changes in the text, references added; matches published version
Limb Darkening and Planetary Transits: Testing Center-to-limb Intensity Variations and Limb-Darkening Directly from Model Stellar Atmospheres
Creators: name: Neilson, Hilding R.
name: McNeil, Joseph T.
name: Ignace, Richard
name: Lester, John B.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The transit method, employed by MOST, \emph{Kepler}, and various ground-based surveys has enabled the characterization of extrasolar planets to unprecedented precision. These results are precise enough to begin to measure planet atmosphere composition, planetary oblateness, star spots, and other phenomena at the level of a few hundred parts-per-million. However, these results depend on our understanding of stellar limb darkening, that is, the intensity distribution across the stellar disk that is sequentially blocked as the planet transits. Typically, stellar limb darkening is assumed to be a simple parameterization with two coefficients that are derived from stellar atmosphere models or fit directly. In this work, we revisit this assumption and compute synthetic planetary transit light curves directly from model stellar atmosphere center-to-limb intensity variations (CLIV) using the plane-parallel \textsc{Atlas} and spherically symmetric \textsc{SAtlas} codes. We compare these light curves to those constructed using best-fit limb-darkening parameterizations. We find that adopting parametric stellar limb-darkening laws lead to systematic differences from the more geometrically realistic model stellar atmosphere CLIV of about 50 -- 100 ppm at the transit center and up to 300 ppm at ingress/egress. While these errors are small they are systematic, and appear to limit the precision necessary to measure secondary effects. Our results may also have a significant impact on transit spectra.
description: 12 pages, 14 figures, accepted for publication in ApJ after revisions
Near-degeneracy effects on the frequencies of rotationally-split mixed modes in red giants
Creators: name: Deheuvels, Sebastien
name: Ouazzani, Rhita-Maria
name: Basu, Sarbani
Publisher: name: arXiv
Year: 2017
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The Kepler space mission has made it possible to measure the rotational splittings of mixed modes in red giants, thereby providing an unprecedented opportunity to probe the internal rotation of these stars. Asymmetries have been detected in the rotational multiplets of several red giants. This is unexpected since all the red giants whose rotation have been measured thus far are found to rotate slowly, and low rotation, in principle, produces symmetrical multiplets. Our aim here is to explain these asymmetries and find a way of exploiting them to probe the internal rotation of red giants. We show that in the cases where asymmetrical multiplets were detected, near-degeneracy effects are expected to occur, because of the combined effects of rotation and mode mixing. Such effects have not been taken into account so far. By using both perturbative and non-perturbative approaches, we show that near-degeneracy effects produce multiplet asymmetries that are very similar to the observations. We then propose and validate a method based on the perturbative approach to probe the internal rotation of red giants using multiplet asymmetries. We successfully apply our method to the asymmetrical $l=2$ multiplets of the Kepler young red giant KIC7341231 and obtain precise estimates of its mean rotation in the core and the envelope. The observed asymmetries are reproduced with a good statistical agreement, which confirms that near-degeneracy effects are very likely the cause of the detected multiplet asymmetries. We expect near-degeneracy effects to be important for $l=2$ mixed modes all along the red giant branch (RGB). For $l=1$ modes, these effects can be neglected only at the base of the RGB. They must therefore be taken into account when interpreting rotational splittings and as shown here, they can bring valuable information about the internal rotation of red giants.
description: Accepted for publication in A&A, 16 pages, 9 figures
Large Magnetic Anisotropy and Magnetostriction in Thin Films of CoV$_2$O$_4$
Creators: name: Kim, Sangsoo
name: Thompson, Christie
name: Xin, Yan
name: Beekman, Christianne
Publisher: name: arXiv
Year: 2022
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Spinel Cobalt Vanadate CoV$_2$O$_4$ has been grown on (001) SrTiO$_3$ substrates. Using torque magnetometry experiments, we find that the previously observed temperature induced anisotropy change, where the easy axis changes from the out of plane [001] direction to a biaxial anisotropy with planar <100> easy axes, occurs in a gradual second-order structural phase transition. This work characterizes this transition and the magnetic anisotropies in the (001), (100), and (-110) rotation planes, and explores their field dependence up to 30~T. Below 80~K, hysteretic features appear around the hard axes, i.e., the out-of-plane direction in (-110) and (010) rotations and the planar <110> directions in (001) rotations. This is due to a Zeeman Energy that originates from the lag of the magnetization with respect to the applied magnetic field as the sample is rotated. The appearance of the hysteresis, which persist up to very high fields, shows that the anisotropy at low temperature is rather strong. Additionally, field dependent distortions to the symmetry of the torque response in increasing applied fields shows that magnetostriction plays a large role in determining the direction and magnitude of the anisotropy.
description: Main text: 9 pages and 6 figures; supplemental materials: 9 pages and 10 figures