cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Discovery of a Cosmological, Relativistic Outburst via its Rapidly Fading Optical Emission
Creators: name: Cenko, S. Bradley
name: Kulkarni, S. R.
name: Horesh, Assaf
name: Corsi, Alessandra
name: Fox, Derek B.
name: Carpenter, John
name: Frail, Dale A.
name: Nugent, Peter E.
name: Perley, Daniel A.
name: Gruber, D.
name: Gal-Yam, Avishay
name: Groot, Paul J.
name: Hallinan, G.
name: Ofek, Eran O.
name: Rau, Arne
name: MacLeod, Chelsea L.
name: Miller, Adam A.
name: Bloom, Joshua S.
name: Filippenko, Alexei V.
name: Kasliwal, Mansi M.
name: Law, Nicholas M.
name: Morgan, Adam N.
name: Polishook, David
name: Poznanski, Dovi
name: Quimby, Robert M.
name: Sesar, Branimir
name: Shen, Ken J.
name: Silverman, Jeffrey M.
name: Sternberg, Assaf
Publisher: name: arXiv
Year: 2013
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We report the discovery by the Palomar Transient Factory (PTF) of the transient source PTF11agg, which is distinguished by three primary characteristics: (1) bright, rapidly fading optical transient emission; (2) a faint, blue quiescent optical counterpart; and (3) an associated year-long, scintillating radio transient. We argue that these observed properties are inconsistent with any known class of Galactic transients, and instead suggest a cosmological origin. The detection of incoherent radio emission at such distances implies a large emitting region, from which we infer the presence of relativistic ejecta. The observed properties are all consistent with the population of long-duration gamma-ray bursts (GRBs), marking the first time such an outburst has been discovered in the distant universe independent of a high-energy trigger. We searched for possible high-energy counterparts to PTF11agg, but found no evidence for associated prompt emission. We therefore consider three possible scenarios to account for a GRB-like afterglow without a high-energy counterpart: an "untriggered" GRB (lack of satellite coverage), an "orphan" afterglow (viewing-angle effects), and a "dirty fireball" (suppressed high-energy emission). The observed optical and radio light curves appear inconsistent with even the most basic predictions for off-axis afterglow models. The simplest explanation, then, is that PTF11agg is a normal, on-axis long-duration GRB for which the associated high-energy emission was simply missed. However, we have calculated the likelihood of such a serendipitous discovery by PTF and find that it is quite small (~ 2.6%). While not definitive, we nonetheless speculate that PTF11agg may represent a new, more common (> 4 times the on-axis GRB rate at 90% confidence) class of relativistic outbursts lacking associated high-energy emission.
description: 45 pages, 7 figures; Resubmitted to ApJ after incorporating referee comments
Tunnelling-induced cosmic bounce in the presence of anisotropies
Creators: name: Alexandre, Jean
name: Clough, Katy
name: Pla, Silvia
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: If we imagine rewinding the universe to early times, the scale factor shrinks and the existence of a finite spatial volume may play a role in quantum tunnelling effects in a closed universe. It has recently been shown that such finite volume effects dynamically generate an effective equation of state that could support a cosmological bounce. In this work we extend the analysis to the case in which a (homogeneous) anisotropy is present, and identify a criteria for a successful bounce in terms of the size of the closed universe and the properties of the quantum field.
description: 9 pages, 5 figures, minor changes, version accepted for publication in Physical Review D
Inter-layer valence bonds and two-component theory for high-$T_c$ superconductivity of La$_{3}$Ni$_{2}$O$_{7}$ under pressure
Creators: name: Yang, Yi-feng
name: Zhang, Guang-Ming
name: Zhang, Fu-Chun
Publisher: name: arXiv
Year: 2023
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The recent discovery of high-$T_{c}$ superconductivity in bilayer nickelate La$_{3}$Ni$_{2}$O$_{7}$ under high pressure has stimulated great interest concerning its pairing mechanism. We argue that the weak coupling model from the almost fully-filled $d_{z^{2}}$ bonding band cannot give rise to its high $T_{c}$, and thus propose a strong coupling model based on local inter-layer spin singlets of Ni-$d_{z^{2}}$ electrons due to their strong on-site Coulomb repulsion. This leads to a minimal effective model that contains local pairing of $d_{z^{2}}$ electrons and a considerable hybridization with near quarter-filled itinerant $d_{x^{2}-y^{2}}$ electrons on nearest-neighbor sites. Their strong coupling provides a unique two-component scenario to achieve high-$T_{c}$ superconductivity. Our theory highlights the importance of the bilayer structure of superconducting La$_{3}$Ni$_{2}$O$_{7}$ and points out a potential route for the exploration of more high-$T_{c}$ superconductors.
description: 6 pages, 3 figures
The vertex connectivity of some classes of divisible design graphs
Creators: name: Panasenko, Dmitry
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: A $k$-regular graph is called a divisible design graph if its vertex set can be partitioned into $m$ classes of size $n$, such that two distinct vertices from the same class have exactly $λ_1$ common neighbours, and two vertices from different classes have exactly $λ_2$ common neighbours. In this paper, we find the vertex connectivity of some classes of divisible design graphs, in particular, we present examples of divisible design graphs, whose vertex connectivity is less than $k$, where $k$ is the degree of a vertex. We also show that the vertex connectivity a divisible design graphs may be less than $k$ by any power of 2.
Multilepton Signatures from Dark Matter at the LHC
Creators: name: Belyaev, Alexander
name: Blumenschein, Ulla
name: Freegard, Arran
name: Moretti, Stefano
name: Sengupta, Dipan
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Leptonic signatures of Dark Matter (DM) are one of the cleanest ways to discover such a secluded form of matter at high energy colliders. We explore the full parameter space relevant to multi-lepton (2- and 3-lepton) signatures at the Large Hadron Collider (LHC) from representative minimal consistent models with scalar and fermion DM. In our analysis, we suggest a new parametrisation of the model parameter spaces in terms of the DM mass and mass differences between DM and its multiplet partners. This parametrisation allows us to explore properties of DM models in their whole parameter space. This approach is generic and quite model-independent since the mass differences are related to the couplings of the DM to the Standard Model (SM) sector. We establish the most up-to-date LHC limits on the inert 2-Higgs Doublet Model (i2HDM) and Minimal Fermion DM (MFDM) model parameter spaces, by using the complementary information stemming from 2- and 3-lepton signatures. We provide a map of LHC efficiencies and cross-section limits for such 2- and 3-lepton signatures allowing one to easily make model-independent reinterpretations of LHC results for analogous classes of models. We also present combined constraints from the LHC, DM relic density and direct search experiments indicating the current status of the i2HDM and MFDM model.
Kazakov-Migdal model on the Graph and Ihara Zeta Function
Creators: name: Matsuura, So
name: Ohta, Kazutoshi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Lattice (hep-lat)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We propose the Kazakov-Migdal model on graphs and show that, when the parameters of this model are appropriately tuned, the partition function is represented by the unitary matrix integral of an extended Ihara zeta function, which has a series expansion by all non-collapsing Wilson loops with their lengths as weights. The partition function of the model is expressed in two different ways according to the order of integration. A specific unitary matrix integral can be performed at any finite $N$ thanks to this duality. We exactly evaluate the partition function of the parameter-tuned Kazakov-Migdal model on an arbitrary graph in the large $N$ limit and show that it is expressed by the infinite product of the Ihara zeta functions of the graph.
description: 33 pages, 6 figures, references added, a figure added, a comment on physical model added, typos corrected
Constraints on Lorentz Invariance Violation from Fermi-Large Area Telescope Observations of Gamma-Ray Bursts
Creators: name: Vasileiou, V.
name: Jacholkowska, A.
name: Piron, F.
name: Bolmont, J.
name: Couturier, C.
name: Granot, J.
name: Stecker, F. W.
name: Cohen-Tanugi, J.
name: Longo, F.
Publisher: name: arXiv
Year: 2013
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
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 analyze the MeV/GeV emission from four bright Gamma-Ray Bursts (GRBs) observed by the Fermi-Large Area Telescope to produce robust, stringent constraints on a dependence of the speed of light in vacuo on the photon energy (vacuum dispersion), a form of Lorentz invariance violation (LIV) allowed by some Quantum Gravity (QG) theories. First, we use three different and complementary techniques to constrain the total degree of dispersion observed in the data. Additionally, using a maximally conservative set of assumptions on possible source-intrinsic spectral-evolution effects, we constrain any vacuum dispersion solely attributed to LIV. We then derive limits on the "QG energy scale" (the energy scale that LIV-inducing QG effects become important, E_QG) and the coefficients of the Standard Model Extension. For the subluminal case (where high energy photons propagate more slowly than lower energy photons) and without taking into account any source-intrinsic dispersion, our most stringent limits (at 95% CL) are obtained from GRB090510 and are E_{QG,1}>7.6 times the Planck energy (E_Pl) and E_{QG,2}>1.3 x 10^11 GeV for linear and quadratic leading order LIV-induced vacuum dispersion, respectively. These limits improve the latest constraints by Fermi and H.E.S.S. by a factor of ~2. Our results disfavor any class of models requiring E_{QG,1} \lesssim E_Pl.
description: Accepted for publication by Physical Review D
Flare-out condition of Morris-Thorne wormhole and finiteness of pressure
Creators: name: Kim, Sung-Won
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Wormhole is defined as the topological structure with the throat connecting two asymptotically flat spaces. In order to have and maintain the structure of the wormhole, there needs the geometrical flare-out condition, i.e., the minimal size at throat. In the case of Morris-Thorne type wormhole, the condition is given by the huge surface tension compared to the energy density times the square of the light speed. In this paper, we re-considered the flare-out condition for the wormhole with the Einstein equation, checked the finiteness of the pressure, and investigated its physical meaning.
A Scattering Amplitude for Massive Particles in AdS
Creators: name: Gadde, Abhijit
name: Sharma, Trakshu
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we propose a conformally covariant momentum space representation of CFT correlation functions. We call it the AdS S-matrix. This representation has the property that it reduces to the S-matrix in the flat space limit. The flat space limit in question is taken by keeping all the particle masses fixed as the operator conformal dimensions go to infinity along with the AdS radius $\mathtt{R}$. We give Feynman-like rules to compute the AdS S-matrix in $1/ \mathtt{R}$ perturbation theory. Moreover, we relate it to the Mellin space representation of the conformal correlators in $1/ \mathtt{R}$ perturbation theory.
description: 42 pages, 5 figures, version 2, minor changes have been made
UniG-Encoder: A Universal Feature Encoder for Graph and Hypergraph Node Classification
Creators: name: Zou, Minhao
name: Gan, Zhongxue
name: Wang, Yutong
name: Zhang, Junheng
name: Sui, Dongyan
name: Guan, Chun
name: Leng, Siyang
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: FOS: Computer and information sciences

description: Graph and hypergraph representation learning has attracted increasing attention from various research fields. Despite the decent performance and fruitful applications of Graph Neural Networks (GNNs), Hypergraph Neural Networks (HGNNs), and their well-designed variants, on some commonly used benchmark graphs and hypergraphs, they are outperformed by even a simple Multi-Layer Perceptron. This observation motivates a reexamination of the design paradigm of the current GNNs and HGNNs and poses challenges of extracting graph features effectively. In this work, a universal feature encoder for both graph and hypergraph representation learning is designed, called UniG-Encoder. The architecture starts with a forward transformation of the topological relationships of connected nodes into edge or hyperedge features via a normalized projection matrix. The resulting edge/hyperedge features, together with the original node features, are fed into a neural network. The encoded node embeddings are then derived from the reversed transformation, described by the transpose of the projection matrix, of the network's output, which can be further used for tasks such as node classification. The proposed architecture, in contrast to the traditional spectral-based and/or message passing approaches, simultaneously and comprehensively exploits the node features and graph/hypergraph topologies in an efficient and unified manner, covering both heterophilic and homophilic graphs. The designed projection matrix, encoding the graph features, is intuitive and interpretable. Extensive experiments are conducted and demonstrate the superior performance of the proposed framework on twelve representative hypergraph datasets and six real-world graph datasets, compared to the state-of-the-art methods. Our implementation is available online at https://github.com/MinhZou/UniG-Encoder.
Classical and relavistic simple wave problems solved with Smoothed Particle Hydrodynamics
Creators: name: Caetano, J V O
name: Nowacki, L S
name: Franção, V S
name: Hirayama, R
name: Pala, K P
name: Sola, J O
name: Grassi, F
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: To simulate the expansion of the matter created in relativistic nuclear collisions, codes in 3+1 dimensions are used and we are developing a new one. To benchmark such codes, the Sod's shock tube is often used. A closely related problem is the one-dimensional expansion of a gas into vacuum. In this paper, we study this problem classically and relativistically with the Smoothed Particle Method and test various techniques to improve the precision and speed of the solution.
description: 5 pages, 2 figures, submitted to XLIV Brazilian Workshop Nuclear Physics 2021
Officers, committees, constitution and by-laws, members, reports of officers and committees
Creators: name: (:Unav)
Publisher: name: Columbia University
Year: 1884
Subjects: Book clubs--Periodicals.
Bibliography--Periodicals.

description: List of publications of the Club from 1884 are contained in 1899 and, with list of exhibition catalogues (previously issued 1900) in 1906- and from 1917 to 1927 in 1928
Mode-cleaning and injection optics of the gravitational-wave detector GEO600
Creators: name: Goßler, S.
name: Casey, M.M.
name: Freise, A.
name: Grant, A.
name: Grote, H.
name: Heinzel, G.
name: Heurs, Michèle
name: Husman, M.E.
name: Kötter, K.
name: Leonhardt, V.
name: Lück, Harald
name: Malec, M.
name: Mossavi, K.
name: Nagano, S.
name: McNamara, P.W.
name: Plissi, M.V.
name: Quetschke, V.
name: Robertson, D.I.
name: Robertson, N.A.
name: Rüdiger, A.
name: Schilling, R.
name: Skeldon, K.D.
name: Strain, K.A.
name: Torrie, C.I.
name: Ward, H.
name: Weiland, U.
name: Willke, B.
name: Winkler, W.
name: Hough, J.
name: Danzmann, K.
Publisher: name: College Park, MD : American Institute of Physics (AIP)
Year: 2003
Subjects: subject: Actuators
subject: Contamination
subject: Detectors
subject: Interferometers
subject: Lasers
subject: Magnets
subject: Pendulums
subject: Refractive index
subject: Resonance
subject: Ultrahigh vacuum
subject: Injection optics
subject: Gravity waves
subject: Dewey Decimal Classification::500 | Naturwissenschaften::530 | Physik
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau

description: A study to investigate the mode-cleaning and injection optics of the gravitational-wave detector GEO600 was presented. The instrument uses two high-finesse triangular ring cavities of 8 m optical wavelength each, as an optical mode-cleaning system. The duty cycle of the system was measured to be 99.7%. It was found that the throughput of the whole modecleaner system is about 50%.
Specific many-electron effects in X-ray spectra of simple metals and graphene
Creators: name: Ovcharenko, R. E.
name: Tupitsyn, I. I.
name: Savinov, E. P.
name: Voloshina, E. N.
name: Paulus, B.
name: Dedkov, Yu. S.
name: Shulakov, A. S.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: In this work the influence of many-electron effects on the shape of characteristic X-ray emission bands of the simple metals Mg and Al are examined by means of ab initio calculations and semi-empirical models. These approaches are also used for the analysis of C K-emission and absorption spectra of graphene. Both, the dynamical screening of the core vacancy and the Auger-effect in the valence band (VB) have been taken into account. Dynamical screening of the core vacancy by valence electrons (the so-called MND effect) is considered ab initio in the framework of density functional theory. The Auger effect in VB was taken into account within a semi-empirical method, approximating the quadratic dependence of the VB hole level width on the difference between the level energy and the Fermi energy. All theoretical spectra are in very good agreement with available experimental data.
description: accepted in Phys. Chem. Chem. Phys
Interpretable inverse-designed cavity for on-chip nonlinear and quantum optics
Creators: name: Jia, Zhetao
name: Qarony, Wayesh
name: Park, Jagang
name: Hooten, Sean
name: Wen, Difan
name: Zhiyenbayev, Yertay
name: Seclì, Matteo
name: Redjem, Walid
name: Dhuey, Scott
name: Schwartzberg, Adam
name: Yablonovitch, Eli
name: Kanté, Boubacar
Publisher: name: arXiv
Year: 2023
Subjects: subject: Optics (physics.optics)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Inverse design is a powerful tool in wave-physics and in particular in photonics for compact, high-performance devices. To date, applications have mostly been limited to linear systems and it has rarely been investigated or demonstrated in the nonlinear regime. In addition, the "black box" nature of inverse design techniques has hindered the understanding of optimized inverse-designed structures. We propose an inverse design method with interpretable results to enhance the efficiency of on-chip photon generation rate through nonlinear processes by controlling the effective phase-matching conditions. We fabricate and characterize a compact, inverse-designed device using a silicon-on-insulator platform that allows a spontaneous four-wave mixing process to generate photon pairs at 1.1MHz with a coincidence to accidental ratio of 162. Our design method accounts for fabrication constraints and can be used for scalable quantum light sources in large-scale communication and computing applications.
Superradiant instabilities of massive bosons around exotic compact objects
Creators: name: Zhou, Lihang
name: Brito, Richard
name: Mai, Zhan-Feng
name: Shao, Lijing
Publisher: name: arXiv
Year: 2023
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Superradiantly unstable ultralight particles around a classical rotating black hole (BH) can form an exponentially growing bosonic cloud, which have been shown to provide an astrophysical probe to detect ultralight particles and constrain their mass. However, the classical BH picture has been questioned, and different theoretical alternatives have been proposed. Exotic compact objects (ECOs) are horizonless alternatives to BHs featuring a reflective surface (with a reflectivity $\mathcal{K}$) in place of the event horizon. In this work, we study superradiant instabilities around ECOs, particularly focusing on the influence of the boundary reflection. We calculate the growth rate of superradiant instabilities around ECOs, and show that the result can be related to the BH case by a correction factor $g_{\mathcal{K}}$, for which we find an explicit analytical expression and a clear physical interpretation. Additionally, we consider the time evolution of superradiant instabilities and find that the boundary reflection can either shorten or prolong the growth timescale. As a result, the boundary reflection alters the superradiance exclusion region on the Regge plane, potentially affecting constraints on the mass of ultralight particles. For a mildly reflective surface ($|\mathcal{K}|\lesssim 0.5$), the exclusion region is not substantially changed, while significant effects from the boundary reflection can occur for an extreme reflectivity ($|\mathcal{K}|\gtrsim0.9$).
description: 12 pages, 5 figures; accepted by PRD
Frequenzabhängigkeit des Ermüdungswiderstandes von hochfestem Beton
Creators: name: Schneider, Sebastian
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2021
Subjects: subject: fatigue
subject: high-strength concrete
subject: load frequency
subject: stress rate
subject: rest periods
subject: temperature
subject: Ermüdung
subject: hochfester Beton
subject: Belastungsfrequenz
subject: Spannungsgeschwindigkeit
subject: Belastungspause
subject: Temperatur
subject: Dewey Decimal Classification::600 | Technik

description: Der Ermüdungswiderstand von hochfestem Beton weist eine divergierende Abhängigkeit von der einwirkenden Belastungsfrequenz auf. Auf hohen Oberspannungsniveaus von Smax > 0,75 führen höhere Belastungsfrequenzen zu höheren Bruchlastwechselzahlen. Auf niedrigeren Oberspannungsniveaus wurde wiederholt eine Umkehr dieses Einflusses beobachtet. Höhere Belastungsfrequenzen führen in diesem Fall zu geringeren Bruchlastwechselzahlen. Bisher existierende Materialmodelle können dieses Materialverhalten nicht abbilden, wodurch die Vergleichbarkeit von verschiedenfrequenten Ermüdungsuntersuchungen sowie die Übertragbarkeit von Laborergebnissen auf reale Beanspruchungssituationen erschwert werden. In der vorliegenden Arbeit wird die frequenzabhängige Entwicklung der Bruchlastwechselzahlen von hochfestem Beton betrachtet. Dabei wird von den Hypothesen ausgegangen, dass die einwirkende Spannungsgeschwindigkeit und die im Probekörper entstehende Temperatur den internen Schädigungsprozess beeinflussen. Höhere Spannungsgeschwindigkeiten reduzieren die Schädigungsprogression wohingegen höhere Temperaturen diese beschleunigen. Um diese Hypothesen versuchstechnisch zu überprüfen, wurden verschiedenfrequente Ermüdungsversuche mit und ohne Belastungspausen durchgeführt. Mithilfe der Belastungspausen wurden die Probekörpertemperaturen der höherfrequenten Versuche an die der ununterbrochenen niederfrequenten Versuche angeglichen. Die Versuchsergebnisse unterstützen letztlich die formulierten Hypothesen und dienen für eine anschließende makroskopische Modellbildung. Auf Grundlage dieser Versuchsergebnisse werden frequenzabhängige Wöhlerlinien entwickelt, die den zeitinvarianten Einfluss der Spannungsgeschwindigkeit und den zeitvarianten Einfluss der Temperatur auf die internen Schädigungsprozesse in sich vereinen. Diese Wöhlerlinien sind in der Lage, den divergierenden Einfluss der Belastungsfrequenz auf die Bruchlastwechselzahlen und somit deren frequenzbedingten Streubereich abzubilden. Um in zukünftigen Ermüdungsversuchen insbesondere die Entwicklung des thermischen-induzierten Schädigungsprozess zu begrenzen, werden zulässige Belastungsfrequenzen und Temperaturerhöhungen vorgeschlagen. Da Beton in realen Tragwerken mit geringeren Belastungsfrequenzen beansprucht wird als in den vorgeschlagenen Versuchskonzepten bzw. in gewöhnlichen Laborversuchen, wurde die Notwendigkeit der frequenzbedingten Reduktion der normativen Bemessungsdruckfestigkeit unter Ermüdungsbeanspruchungen fcd,fat untersucht und bestätigt.
Peeling away neutron skin in ultracentral collisions of relativistic nuclei
Creators: name: Kozyrev, Nikita
name: Svetlichnyi, Aleksandr
name: Nepeivoda, Roman
name: Pshenichnov, Igor
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Theory (nucl-th)
subject: Nuclear Experiment (nucl-ex)
subject: FOS: Physical sciences

description: In heavy nuclei the ratio between local densities of neutrons and protons increases towards the nuclear periphery. The excess of neutrons is known as the neutron skin (NS) with a subtle difference ($<0.5$~fm) between the r.m.s radii of the distributions of neutrons and protons. We show that the presence of NS in $^{208}$Pb leads to extra spectator neutrons in ultracentral $^{208}$Pb--$^{208}$Pb collisions at the CERN SPS and LHC. The yields of spectator neutrons and protons were calculated within a new version of Abrasion-Ablation Monte Carlo for Colliders model (AAMCC-MST) taking into account NS and pre-equilibrium clustering of spectator matter. While the average numbers of spectator neutrons and protons in ultracentral collisions vary insignificantly, the cross sections of emission of certain numbers of spectator neutrons in events with 0,1,...5 spectator protons are changed by 50--250\%, depending on the thickness of NS. These cross sections are less sensitive to other parameters in calculations, and their measurements in the ALICE experiment at the LHC will make it possible to restrict the existing variety of neutron density parameterizations in $^{208}$Pb.
description: 23 pages, 14 figures, 5 tables
Intelligent Database Architecture for High-Integrity Urban Navigation
Creators: name: Ruwisch, Fabian
name: Ren, Le
name: Skupin, Christian
name: Kersten, Tobias
name: O'Connor, Marcus
name: Schön, Steffen
name: Wübbena, Temmo
Publisher: name: Hannover : Institutionelles Repositorium der Leibniz Universität Hannover
Year: 2022
Subjects: subject: Line-of-sight
subject: urban navigation
subject: GNSS
subject: Multipath
subject: Sichtlinie
subject: innerstädtsiche Navigation
subject: Mehrwege
subject: Dewey Decimal Classification::500 | Naturwissenschaften::520 | Astronomie, Kartographie
subject: Dewey Decimal Classification::600 | Technik::620 | Ingenieurwissenschaften und Maschinenbau::621 | Angewandte Physik::621,3 | Elektrotechnik, Elektronik

description: Accuracy, integrity and availability requirements are very stringent in urban navigation and autonomous driving. The GNSS sensor is the only one that provides self-localisation in a global coordinate system. The challenge ist to model non line-of-sight (NLOS) and multipath scenarios in urban areas. To meeth the high accuracy requirements, these distortions has to be known and corrected. Ray-tracing approaches are real-time capable but require a high computational load. The vision for this contribution is the correction of GNSS multipath for relaiable autonomous localisation of highly automated vehicles using an intelligent database structure.
In-situ synthesis and characterization of polyaniline -CaCu3Ti4O12 nano crystal composites
Creators: name: Thomas, P.
name: Dwarakanath, K.
name: Varma, K. B. R.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: High dielectric constant nano composite of Polyaniline (PANI) CaCu3Ti4O12 (CCTO) was synthesized using a simple procedure involving in-situ polymerization of aniline in dil. HCl. The PANI and the composite were subjected to X-ray diffraction, Fourier transform infrared, Thermo gravimetric, Scanning electron microscopy and Transmission electron microscopy analyses. The presence of the nano crystallites of CCTO embedded in the nanofibers of PANI matrix was established by TEM. Frequency dependent characteristics of the dielectric constant, dielectric loss and AC conductivity were studied for the PANI and the composites. The dielectric constant increased as the CCTO content increased in PANI but decreased with increasing frequency of measurement. The dielectric loss was two times less than the value obtained for pure PANI around 100Hz. The AC conductivity increased slightly upto 2kHz as the CCTO content increased in the PANI which was attributed to the polarization of the charge carriers.
Light transport through amorphous photonic materials with localization and bandgap regimes
Creators: name: Scheffold, Frank
name: Haberko, Jakub
name: Magkiriadou, Sofia
name: Froufe-Pérez, Luis S.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Optics (physics.optics)
subject: Disordered Systems and Neural Networks (cond-mat.dis-nn)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: We propose a framework that unifies the description of light transport in three-dimensional amorphous dielectric materials that exhibit both localization and a photonic bandgap. To this end, we argue that coherent reflection near and in the bandgap attenuates the generation of diffuse or localized photons. Using the self-consistent theory of localization and considering the density of states of photons, we can quantitatively describe all transport regimes: Transparency, light diffusion, localization, and bandgap. Comparing the model with numerical data on optical transport in hyperuniform dielectric networks confirms our findings.
description: accepted for publication in Physical Review Letters
The Impact of Thermal Conductivity and Diffusion Rates on Water Vapor Transport through Gas Diffusion Layers
Creators: name: Burlatsky, S. F.
name: Atrazhev, V. V.
name: Gummallaa, M.
name: Condita, D.
name: Liua, F.
Publisher: name: arXiv
Year: 2013
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Water management in a hydrogen polymer electrolyte membrane (PEM) fuel cell is critical for performance. The impact of thermal conductivity and water vapor diffusion coefficients in a gas diffusion layer (GDL) has been studied by a mathematical model. The fraction of product water that is removed in the vapour phase through the GDL as a function of GDL properties and operating conditions has been calculated and discussed. Furthermore, the current model enables identification of conditions when condensation occurs in each GDL component and calculation of temperature gradient across the interface between different layers, providing insight into the overall mechanism of water transport in a given cell design. Water transport mode and condensation conditions in the GDL components depend on the combination of water vapor diffusion coefficients and thermal conductivities of the GDL components. Different types of GDL and water removal scenarios have been identified and related to experimentally-determined GDL properties.
title: Hasmukhlal Dhirajlal Sankalia - Moreshwar Gangadhar Dikshit, Excavations at Brahmapuri (Kolhapur) 1945-46
Creators: name: Klumbach, Heinz
Publisher: name: University Library Heidelberg
Year: 2016

description: Rezension zu: H. D. Sankalia - M. G. Dikshit, Excavations at Brahmapuri (Kolhapur) 1945-46, Poona 1952. XV + 154 Seiten, 1 Plan, 31 Abb., 38 Tafeln.
Scale coupling and interface pinning effects in the phase-field-crystal model
Creators: name: Huang, Zhi-Feng
Publisher: name: arXiv
Year: 2012
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Effects of scale coupling between mesoscopic slowly-varying envelopes of liquid-solid profile and the underlying microscopic crystalline structure are studied in the phase-field-crystal (PFC) model. Such scale coupling leads to nonadiabatic corrections to the PFC amplitude equations, the effect of which increases strongly with decreasing system temperature below the melting point. This nonadiabatic amplitude representation is further coarse-grained for the derivation of effective sharp-interface equations of motion in the limit of small but finite interface thickness. We identify a generalized form of the Gibbs-Thomson relation with the incorporation of coupling and pinning effects of the crystalline lattice structure. This generalized interface equation can be reduced to the form of a driven sine-Gordon equation with KPZ nonlinearity, and be combined with other two dynamic equations in the sharp interface limit obeying the conservation condition of atomic number density in a liquid-solid system. A sample application to the study of crystal layer growth is given, and the corresponding analytic solutions showing lattice pinning and depinning effects and two distinct modes of continuous vs. nucleated growth are presented. We also identify the universal scaling behaviors governing the properties of pinning strength, surface tension, interface kinetic coefficient, and activation energy of atomic layer growth, which accommodate all range of liquid-solid interface thickness and different material elastic modulus.
description: 15 pages, 6 figures; to be published in Phys. Rev. E
Giant Shear Displacement by Light-Induced Raman Force in Bilayer Graphene
Creators: name: Rostami, Habib
Publisher: name: arXiv
Year: 2022
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Coherent excitation of shear phonons in van der Waals layered materials is a non-destructive mechanism to fine-tune the electronic state of the system. We develop a diagrammatic theory for the displacive Raman force and apply it to the shear phonon's dynamics. We obtain a rectified Raman force density in bilayer graphene of the order of ${\cal F}\sim 10{\rm nN/nm^2}$ leading to a giant shear displacement $Q_0 \sim 50$pm for an intense infrared laser. We discuss both circular and linear displacive Raman forces. We show that the laser frequency and polarization can effectively tune $Q_0$ in different electronic doping, temperature, and scattering rates. We reveal that the finite $Q_0$ induces a Dirac crossing pair in the low-energy dispersion that photoemission spectroscopy can probe. Our finding provides a systematic pathway to simulate and analyze the coherent manipulation of staking order in the heterostructures of layered materials by laser irradiation.
description: 6 Pages, 3 Figures, Supplementary: As ancillary file
Velocity Effects on an Accelerated Unruh-DeWitt Detector
Creators: name: Abdolrahimi, Shohreh
Publisher: name: arXiv
Year: 2013
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We analyze the response of an Unruh-DeWitt detector moving along an unbounded spatial trajectory in a two-dimensional spatial plane with constant independent magnitudes of both the four-acceleration and of a timelike proper time derivative of the four-accelration. In a Fermi-Walker frame moving with the detector, the direction of the acceleration rotates at a constant rate around a great circle. This is the motion of a charge in a uniform electric field when in the frame of the charge there is both an electric and a magnetic field. We compare the response of this detector to a detector moving with constant velocity in a thermal bath of the corresponding temperature for non-relativistic velocities, and in two regimes: ultraviolet and infrared. In infrared regime, the detector in the Minkowski space-time moving along the spatially two-dimensional trajectory should move with a higher speed to keep up with the same excitation rate of the inertial detector in a thermal bath. In ultraviolet regime, the dominant modification in the response of this detector compared to the black body spectrum of Unruh radiation is the same as the dominant modification perceived by a detector moving with constant velocity in a thermal bath.
description: (7 pages)
Additional file 1 of H2 generated by fermentation in the human gut microbiome influences metabolism and competitive fitness of gut butyrate producers
Creators: name: Campbell, Austin
name: Gdanetz, Kristi
name: Schmidt, Alexander W.
name: Schmidt, Thomas M.
Publisher: name: figshare
Year: 2023
Subjects: subject: Biochemistry
subject: Microbiology
subject: FOS: Biological sciences
subject: Genetics
subject: Physiology
subject: Pharmacology
subject: 39999 Chemical Sciences not elsewhere classified
subject: FOS: Chemical sciences
subject: Ecology
subject: Immunology
subject: FOS: Clinical medicine
subject: 69999 Biological Sciences not elsewhere classified
subject: Cancer

description: Additional file 1: Figures S1 -Figure S4.
Beta-decay implications for the W-boson mass anomaly
Creators: name: Cirigliano, Vincenzo
name: Dekens, Wouter
name: de Vries, Jordy
name: Mereghetti, Emanuele
name: Tong, Tom
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: We point out the necessity to consider $β$-decay observables in resolutions of the $W$-boson anomaly in the Standard Model Effective Field Theory that go beyond pure oblique corrections. We demonstrate that present global analyses that explain the $W$-boson mass anomaly predict a large, percent-level, violation of first-row CKM unitarity. We investigate what solutions to the $W$-boson mass anomaly survive after including $β$-decay constraints.
Learning Deductive Reasoning from Synthetic Corpus based on Formal Logic
Creators: name: Morishita, Terufumi
name: Morio, Gaku
name: Yamaguchi, Atsuki
name: Sogawa, Yasuhiro
Publisher: name: arXiv
Year: 2023
Subjects: subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: Machine Learning (cs.LG)
subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences

description: We study a synthetic corpus based approach for language models (LMs) to acquire logical deductive reasoning ability. The previous studies generated deduction examples using specific sets of deduction rules. However, these rules were limited or otherwise arbitrary, limiting the generalizability of acquired reasoning ability. We rethink this and adopt a well-grounded set of deduction rules based on formal logic theory, which can derive any other deduction rules when combined in a multistep way. Then, using the proposed corpora, which we name FLD (Formal Logic Deduction), we first evaluate and analyze the logical reasoning ability of the latest LLMs. Even GPT-4 can solve only half of the problems, suggesting that pure logical reasoning isolated from knowledge is still challenging for the LLMs, and additional training specialized in logical reasoning is indeed essential. We next empirically verify that LMs trained on FLD corpora acquire more generalizable reasoning ability. Furthermore, we identify the aspects of reasoning ability on which deduction corpora can enhance LMs and those on which they cannot, and discuss future directions on each aspect. The released corpora serve both as learning resources and as challenging benchmarks.
Renormalization Method and Mirror Symmetry
Creators: name: Li, Si
Publisher: name: arXiv
Year: 2012
Subjects: subject: Algebraic Geometry (math.AG)
subject: High Energy Physics - Theory (hep-th)
subject: Quantum Algebra (math.QA)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: This is a brief summary of our works [arXiv:1112.4063, arXiv:1201.4501] on constructing higher genus B-model from perturbative quantization of BCOV theory. We analyze Givental's symplectic loop space formalism in the context of B-model geometry on Calabi-Yau manifolds, and explain the Fock space construction via the renormalization techniques of gauge theory. We also give a physics interpretation of the Virasoro constraints as the symmetry of the classical BCOV action functional, and discuss the Virasoro constraints in the quantum theory.
Denoising diffusion-based MRI to CT image translation enables automated spinal segmentation
Creators: name: Graf, Robert
name: Schmitt, Joachim
name: Schlaeger, Sarah
name: Möller, Hendrik Kristian
name: Sideri-Lampretsa, Vasiliki
name: Sekuboyina, Anjany
name: Krieg, Sandro Manuel
name: Wiestler, Benedikt
name: Menze, Bjoern
name: Rueckert, Daniel
name: Kirschke, Jan Stefan
Publisher: name: arXiv
Year: 2023
Subjects: subject: Image and Video Processing (eess.IV)
subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Machine Learning (cs.LG)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences
subject: I.2.1
subject: 68T99 68U10

description: Background: Automated segmentation of spinal MR images plays a vital role both scientifically and clinically. However, accurately delineating posterior spine structures presents challenges. Methods: This retrospective study, approved by the ethical committee, involved translating T1w and T2w MR image series into CT images in a total of n=263 pairs of CT/MR series. Landmark-based registration was performed to align image pairs. We compared 2D paired (Pix2Pix, denoising diffusion implicit models (DDIM) image mode, DDIM noise mode) and unpaired (contrastive unpaired translation, SynDiff) image-to-image translation using "peak signal to noise ratio" (PSNR) as quality measure. A publicly available segmentation network segmented the synthesized CT datasets, and Dice scores were evaluated on in-house test sets and the "MRSpineSeg Challenge" volumes. The 2D findings were extended to 3D Pix2Pix and DDIM. Results: 2D paired methods and SynDiff exhibited similar translation performance and Dice scores on paired data. DDIM image mode achieved the highest image quality. SynDiff, Pix2Pix, and DDIM image mode demonstrated similar Dice scores (0.77). For craniocaudal axis rotations, at least two landmarks per vertebra were required for registration. The 3D translation outperformed the 2D approach, resulting in improved Dice scores (0.80) and anatomically accurate segmentations in a higher resolution than the original MR image. Conclusion: Two landmarks per vertebra registration enabled paired image-to-image translation from MR to CT and outperformed all unpaired approaches. The 3D techniques provided anatomically correct segmentations, avoiding underprediction of small structures like the spinous process.
description: 35 pages, 7 figures, Code and a model weights available https://doi.org/10.5281/zenodo.8221159 and https://doi.org/10.5281/zenodo.8198697
Schwarzian for colored Jackiw-Teitelboim gravity
Creators: name: Alkalaev, K. B.
name: Joung, Euihun
name: Yoon, Junggi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We study the boundary effective action of the colored version of the Jackiw-Teitelboim (JT) gravity. We derive the boundary action, which is the color generalization of the Schwarzian action, from the $su(N,N)$ BF formulation of the colored JT gravity. Using different types of the $SU(N,N)$ group decompositions both the zero and finite temperature cases are elaborated. We provide the semi-classical perturbative analysis of the boundary action and discuss the instability of the spin-1 mode and its implication for the quantum chaos. A rainbow-AdS$_2$ geometry is introduced where the color gauge symmetry is spontaneously broken.
description: 40 pages + appendix; v2 minor corrections, reference added; v3 minor correction, published version
Stochastic quantization and holographic Wilsonian renormalization group of conformally coupled scalar in AdS$_{4}$
Creators: name: Lee, Jun Hyeok
name: Oh, Jae-Hyuk
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we explore the relationship between holographic Wilsonian renormalization groups and stochastic quantization in conformally coupled scalar theory in AdS$_{4}$. The relationship between these two different frameworks is firstly proposed in arXiv:1209.2242 and tested in various free theories. However, research on the theory with interactions has recently begun. In this paper, we show that the stochastic four-point function obtained by the Langevin equation is completely captured by the holographic quadruple trace deformation when the Euclidean action $S_{E}$ is given by $S_{E}=-2I_{os}$ where $I_{os}$ is the holographic on-shell action in the conformally coupled scalar theory in AdS$_{4},$ together with a condition that the stochastic fictitious time $t$ is also identified with AdS radial variable $r$. We extensively explore a case that the boundary condition on the conformal boundary is Dirichlet boundary condition, and in that case, the stochastic three-point function trivially vanishes. This agrees with that the holographic triple trace deformation vanishes when Dirichlet boundary condition is applied on the conformal boundary.
description: 17+1 pages