cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On special Riemann xi function formulae of Hardy involving the digamma function
Creators: name: Patkowski, Alexander E
Publisher: name: arXiv
Year: 2017
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics

description: We consider some properties of integrals considered by Hardy and Koshliakov, and which have also been further extended recently by Dixit. We establish a new general integral formula from some observations about the digamma function. We also obtain lower and upper bounds for Hardy's integral through properties of the digamma function.
description: Expanded the exposition
Data-driven distributed MPC of dynamically coupled linear systems
Creators: name: Köhler, Matthias
name: Berberich, Julian
name: Müller, Matthias A.
name: Allgöwer, Frank
Publisher: name: arXiv
Year: 2022
Subjects: subject: Systems and Control (eess.SY)
subject: Optimization and Control (math.OC)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Mathematics

description: In this paper, we present a data-driven distributed model predictive control (MPC) scheme to stabilise the origin of dynamically coupled discrete-time linear systems subject to decoupled input constraints. The local optimisation problems solved by the subsystems rely on a distributed adaptation of the Fundamental Lemma by Willems et al., allowing to parametrise system trajectories using only measured input-output data without explicit model knowledge. For the local predictions, the subsystems rely on communicated assumed trajectories of neighbours. Each subsystem guarantees a small deviation from these trajectories via a consistency constraint. We provide a theoretical analysis of the resulting non-iterative distributed MPC scheme, including proofs of recursive feasibility and (practical) stability. Finally, the approach is successfully applied to a numerical example.
Poisson manifolds and their associated stacks
Creators: name: Villatoro, Joel
Publisher: name: arXiv
Year: 2017
Subjects: subject: Symplectic Geometry (math.SG)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53D17, 22A22, 14A20

description: We associate to any integrable Poisson manifold a stack, i.e. a category fibered in groupoids over a site. The site in question has objects Dirac manifolds and morphisms pairs consisting of a smooth map and a closed 2-form. We show that two Poisson manifolds are symplectically Morita equivalent if and only if their associated stacks are isomorphic.
description: Made several improvements to the exposition and fixed typos
Magnon squeezing enhanced ground-state cooling in cavity magnomechanics
Creators: name: Asjad, M.
name: Li, Jie
name: Zhu, Shi-Yao
name: You, J. Q.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Cavity magnomechanics has recently become a new platform for studying macroscopic quantum phenomena. The magnetostriction induced vibration mode of a large-size ferromagnet or ferrimagnet reaching its ground state represents a genuine macroscopic quantum state. Here we study the ground-state cooling of the mechanical vibration mode in a cavity magnomechanical system, and focus on the role of magnon squeezing in improving the cooling efficiency. The magnon squeezing is obtained by exploiting the magnon self-Kerr nonlinearity. We find that the magnon squeezing can significantly and even completely suppress the magnomechanical Stokes scattering. It thus becomes particularly useful in realizing ground-state cooling in the unresolved-sideband regime, where the conventional sideband cooling protocols become inefficient. We also find that the coupling to the microwave cavity plays only an adverse effect in mechanical cooling. This makes essentially the two-mode magnomechanical system (without involving the microwave cavity) a preferred system for cooling the mechanical motion, in which the magnon mode is established by a uniform bias magnetic field and a microwave drive field.
description: Contribution to the Special Topic: Cavity Optomechanics in Fundamental Research
Shortened universal cycles for permutations
Creators: name: Kirsch, Rachel
name: Lidický, Bernard
name: Sibley, Clare
name: Sprangel, Elizabeth
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics

description: Kitaev, Potapov, and Vajnovszki [On shortening u-cycles and u-words for permutations, Discrete Appl. Math, 2019] described how to shorten universal words for permutations, to length $n!+n-1-i(n-1)$ for any $i \in [(n-2)!]$, by introducing incomparable elements. They conjectured that it is also possible to use incomparable elements to shorten universal cycles for permutations to length $n!-i(n-1)$ for any $i \in [(n-2)!]$. In this note we prove their conjecture. The proof is constructive, and, on the way, we also show a new method for constructing universal cycles for permutations.
description: 13 pages, 10 figures
Towards a heralded eigenstate preserving measurement of multi-qubit parity in circuit QED
Creators: name: Huembeli, Patrick
name: Nigg, Simon E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Eigenstate-preserving multi-qubit parity measurements lie at the heart of stabilizer quantum error correction, which is a promising approach to mitigate the problem of decoherence in quantum computers. In this work we explore a high-fidelity, eigenstate-preserving parity readout for superconducting qubits dispersively coupled to a microwave resonator, where the parity bit is encoded in the amplitude of a coherent state of the resonator. Detecting photons emitted by the resonator via a current biased Josephson junction yields information about the parity bit. We analyse theoretically the measurement back-action in the limit of a strongly coupled fast detector and show that in general such a parity measurement, while approximately Quantum Non-Demolition (QND) is not eigenstate-preserving. To remediate this shortcoming we propose a simple dynamical decoupling technique during photon detection, which greatly reduces decoherence within a given parity subspace. Furthermore, by applying a sequence of fast displacement operations interleaved with the dynamical decoupling pulses, the natural bias of this binary detector can be efficiently suppressed. Finally, we introduce the concept of a heralded parity measurement, where a detector click guarantees successful multi-qubit parity detection even for finite detection efficiency.
Decoupling Nuclear Spins via Interaction-Induced Freezing in Nitrogen Vacancy Centers in Diamond
Creators: name: Kejriwal, Abhishek
name: Shishir, Dasika
name: Pujari, Sumiran
name: Saha, Kasturi
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: Nitrogen-Vacancy (NV) centers in diamonds provide a room-temperature platform for various emerging quantum technologies, e.g. the long nuclear spin coherence times as potential quantum memory registers. We demonstrate a freezing protocol for an NV center to isolate its intrinsic nuclear spin from a noisy electromagnetic environment. Any initial state of the nuclear spin can be frozen when the hyperfine-coupled electron and nuclear spins are simultaneously driven with unequal Rabi frequencies. Through numerical simulations, we show that our protocol can effectively shield the nuclear spin from strong drive or noise fields. We also observe a clear suppression of quantum correlations in the frozen nuclear spin regime by measuring the quantum discord of the electron-nuclear spin system. These features can be instrumental in extending the storage times of NV nuclear-spin based quantum memories in hybrid quantum systems.
Solar calibration of $α_{\rm MLT}$ using ÆSOPUS opacities in MESA
Creators: name: Cinquegrana, Giulia C
name: Joyce, Meridith
Publisher: name: arXiv
Year: 2022
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: The simplistic but ubiquitous Mixing Length Theory (MLT) formalism is used to model convective energy transport within 1D stellar evolution calculations. The formalism relies on the free parameter $α_{\rm MLT}$, which must be independently calibrated within each stellar evolution program and for any given set of physical assumptions. We present a solar calibration of $α_{\text{MLT}}$ appropriate for use with the AESOPUS opacities, which have recently been made available for use with the MESA stellar evolution software. We report a calibrated value of $α_{\rm MLT}=1.931$ and demonstrate the impact of using an appropriately calibrated value in simulations of a $3 M_{\odot}$ asymptotic giant branch star.
description: 4 pages, 1 figure. Accepted for publication in RNAAS
On the slice genus of quasipositive knots in indefinite 4-manifolds
Creators: name: Baraglia, David
Publisher: name: arXiv
Year: 2022
Subjects: subject: Geometric Topology (math.GT)
subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 57K10, 57K41

description: Let $X$ be a closed indefinite $4$-manifold with $b_+(X) = 3 \; ({\rm mod} \; 4)$ and with non-vanishing mod $2$ Seiberg--Witten invariants. We prove a new lower bound on the genus of a properly embedded surface in $X \setminus B^4$ representing a given homology class and with boundary a quasipositive knot $K \subset S^3$. In the null-homologous case our inequality implies that the minimal genus of such a surface is equal to the slice genus of $K$. If $X$ is symplectic then our lower bound differs from the minimal genus by at most $1$ for any homology class that can be represented by a symplectic surface. Along the way, we also prove an extension of the adjunction inequality for closed $4$-manifolds to classes of negative self-intersection without requiring $X$ to be of simple type.
description: 11 pages, accepted version. To appear in Selecta Math
Interface networks in models of competing alliances
Creators: name: Pereira, T. A.
name: Menezes, J.
name: Losano, L.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Pattern Formation and Solitons (nlin.PS)
subject: Physics and Society (physics.soc-ph)
subject: FOS: Physical sciences

description: We study a subclass of the May-Leonard stochastic model with an arbitrary, even number of species, leading to the arising of two competing partnerships where individuals are indistinguishable. By carrying out a series of accurate numerical stochastic simulations, we show that alliances compete each other forming spatial domains bounded by inter- faces of empty sites. We solve numerically the mean field equations associated to the stochastic model in one and two spatial dimensions. We demonstrate that the stationary interface profile presents topological properties which are related to the asymptotic spa- tial distribution of species of enemy alliances far away from the interface core. Finally, we introduce a theoretical approach to model the formation of stable interfaces using spontaneous breaking of a discrete symmetry. We show that all the results provided by the soliton topological model, presented here for the very first time, are in agreement with the stochastic simulations and may be used as a tool for understanding the complex biodiversity in Nature.
description: 7 pages, 8 figures
Supersymmetric SYK model and random matrix theory
Creators: name: Li, Tianlin
name: Liu, Junyu
name: Xin, Yuan
name: Zhou, Yehao
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: In this paper, we investigate the effect of supersymmetry on the symmetry classification of random matrix theory ensembles. We mainly consider the random matrix behaviors in the $\mathcal{N}=1$ supersymmetric generalization of the Sachdev-Ye-Kitaev (SYK) model, a toy model for the two-dimensional quantum black hole with supersymmetric constraint. Some analytical arguments and numerical results are given to show that the statistics of the supersymmetric SYK model could be interpreted as random matrix theory ensembles, with a different eight-fold classification from the original SYK model and some new features. The time-dependent evolution of the spectral form factor is also investigated, where predictions from random matrix theory are governing the late time behavior of the chaotic Hamiltonian with supersymmetry.
description: Published version; Further revisions about statements and presentations
Accretion of the Vlasov gas onto a Schwarzschild-like black hole
Creators: name: Cai, Ziqiang
name: Yang, Rong-Jia
Publisher: name: arXiv
Year: 2022
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We consider spherical steady accretion of the relativistic Vlasov gas onto a Schwarzschild-like black hole. We determine the expressions for the particle current density and accretion rate and present the limiting expressions for the mass accretion rate at high and low temperature. The results show that the parameter characterizing the breaking of Lorentz symmetry can affects the radial component of the particle current density and the mass accretion rate.
description: 15 pages, 9 figures, some figures added
AdaMCT: Adaptive Mixture of CNN-Transformer for Sequential Recommendation
Creators: name: Jiang, Juyong
name: Zhang, Peiyan
name: Luo, Yingtao
name: Li, Chaozhuo
name: Kim, Jae Boum
name: Zhang, Kai
name: Wang, Senzhang
name: Xie, Xing
name: Kim, Sunghun
Publisher: name: arXiv
Year: 2022
Subjects: subject: Information Retrieval (cs.IR)
subject: FOS: Computer and information sciences

description: Sequential recommendation (SR) aims to model users dynamic preferences from a series of interactions. A pivotal challenge in user modeling for SR lies in the inherent variability of user preferences. An effective SR model is expected to capture both the long-term and short-term preferences exhibited by users, wherein the former can offer a comprehensive understanding of stable interests that impact the latter. To more effectively capture such information, we incorporate locality inductive bias into the Transformer by amalgamating its global attention mechanism with a local convolutional filter, and adaptively ascertain the mixing importance on a personalized basis through layer-aware adaptive mixture units, termed as AdaMCT. Moreover, as users may repeatedly browse potential purchases, it is expected to consider multiple relevant items concurrently in long-/short-term preferences modeling. Given that softmax-based attention may promote unimodal activation, we propose the Squeeze-Excitation Attention (with sigmoid activation) into SR models to capture multiple pertinent items (keys) simultaneously. Extensive experiments on three widely employed benchmarks substantiate the effectiveness and efficiency of our proposed approach. Source code is available at https://github.com/juyongjiang/AdaMCT.
description: Accepted by CIKM 2023
Corona effect in AA collisions at LHC
Creators: name: Pantuev, V. S.
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Following our earlier finding based on RHIC data on the dominant jet production from nucleus corona region, we reconsider this effect in nucleus-nucleus collisions at LHC energy. Our hypothesis was based on experimental data, which raised the idea of a finite formation time for the produced medium. At RHIC energy and in low density corona region this time reaches about 2 fm/c. All observed high p_t particles are produced in the corona region and have a chance to escape during this 2 fm/c. After that, the formed high density matter absorbs all jets. Following this hypothesis, the nuclear modification factor R_{AA} should be independent on particle momentum and be flat versus p_t. At the same time, we describe the finite azimuthal anisotropy of high p_t particles, v_2. A separate prediction held that, at LHC energy, the formation time in the corona region should be two times smaller, about 1 fm/c. New data at LHC show that R_{AA} is not flat and is rising with p_t. We add to our original hypothesis an assumption that a fast parton traversing the produced medium loses the fixed portion of its energy. A shift of about 7 GeV (I would call it as a parton binding energy) from the original power law p^{-6} production cross section in pp explains well all the observed R_{AA} dependencies. The shift of about 7 GeV is also valid at RHIC energy, where the cross section follows a power law with about p^{-8} and this shift explains a very slow rise of R_{AA} seen for neutral pions with p_t above 15 GeV/c. We also show that the observed at LHC dependence of v_2 at high p_t and our previous predictions agree.
description: Published version, 4 pages, 5 figures. Only on-line abstract changed by adding notation "parton binding energy"
Simulated redistricting plans for the analysis and evaluation of redistricting in the United States
Creators: name: McCartan, Cory
name: Kenny, Christopher T.
name: Simko, Tyler
name: Garcia, George
name: Wang, Kevin
name: Wu, Melissa
name: Kuriwaki, Shiro
name: Imai, Kosuke
Publisher: name: arXiv
Year: 2022
Subjects: subject: Applications (stat.AP)
subject: Computers and Society (cs.CY)
subject: FOS: Computer and information sciences

description: This article introduces the 50stateSimulations, a collection of simulated congressional districting plans and underlying code developed by the Algorithm-Assisted Redistricting Methodology (ALARM) Project. The 50stateSimulations allow for the evaluation of enacted and other congressional redistricting plans in the United States. While the use of redistricting simulation algorithms has become standard in academic research and court cases, any simulation analysis requires non-trivial efforts to combine multiple data sets, identify state-specific redistricting criteria, implement complex simulation algorithms, and summarize and visualize simulation outputs. We have developed a complete workflow that facilitates this entire process of simulation-based redistricting analysis for the congressional districts of all 50 states. The resulting 50stateSimulations include ensembles of simulated 2020 congressional redistricting plans and necessary replication data. We also provide the underlying code, which serves as a template for customized analyses. All data and code are free and publicly available. This article details the design, creation, and validation of the data.
description: 11 pages, 3 figures
Amplitudes for Astrophysicists: Known Knowns
Creators: name: Burger, Daniel J.
name: Carballo-Rubio, Raúl
name: Moynihan, Nathan
name: Murugan, Jeff
name: Weltman, Amanda
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: The use of quantum field theory to understand astrophysical phenomena is not new. However, for the most part, the methods used are those that have been developed decades ago. The intervening years have seen some remarkable developments in computational quantum field theoretic tools. In particle physics, this technology has facilitated calculations that, even ten years ago would have seemed laughably difficult. It is remarkable, then, that most of these new techniques have remained firmly within the domain of high energy physics. We would like to change this. As alluded to in the title, this is the first in a series of papers aimed at showcasing the use of modern on-shell methods in the context of astrophysics and cosmology. In this first article, we use the old problem of the bending of light by a compact object as an anchor to pedagogically develop these new computational tools. Once developed, we then illustrate their power and utility with an application to the scattering of gravitational waves.
description: 50 pages (sorry!) but lots of figures, some worked examples and a glossary. v2: now with feynman diagrams and added references v3: updated to match published version
Méthodologie de recherche de l'information et de documentation en SIC
Creators: name: AZILAN, Innocent
Publisher: name: Zenodo
Year: 2024

description: Cette présentation a été faite dans le cadre d'un séminaire au sein du laboratoire Centre d'Etudes et de Recherches sur les Organisations, la Communication et l'Education (CEROCE), à l'Université de Lomé (Togo). Elle porte sur les méthodologies de recherche de l'information et de documentation en SIC. Elle revient principalement sur l'utilisation du logiciel Zotero pour la gestion de la bibliographie. Le séminaire a été coanimée avec Dr Sabin Sonhaye (Maître de conférences).
Large Neutrino Asymmetry from TeV Scale Leptogenesis
Creators: name: Borah, Debasish
name: Dasgupta, Arnab
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: We study a class of leptogenesis scenarios with decay or scattering being the source of lepton asymmetry, which can not only give rise to the observed baryon asymmetry in the universe but also can leave behind a large remnant neutrino asymmetry. Such large neutrino asymmetry can not only be probed at future cosmic microwave background (CMB) experiments but is also motivating due to its possible role in solving the recently reported anomalies in $^4{\rm He}$ measurements. Additionally, such large neutrino asymmetry also offers the possibility of cogenesis if dark matter is in the form of a sterile neutrino resonantly produced in the early universe via Shi-Fuller mechanism. Considering $1 \rightarrow 2, 1 \rightarrow 3$ as well as $2 \rightarrow 2$ processes to be responsible for generating the asymmetries, we show that only TeV scale leptogenesis preferably of $1 \rightarrow N \, (N \geq 3)$ type can generate the required lepton asymmetry around sphaleron temperature while also generating a large neutrino asymmetry $\sim \mathcal{O}(10^{-2})$ by the epoch of the big bang nucleosynthesis. While such low scale leptogenesis can have tantalising detection prospects at laboratory experiments, the indication of a large neutrino asymmetry provides a complementary indirect signature.
description: 11 pages, 6 captioned figures, matches version published in Phys. Rev. D
Triviality of Equivariant Maps in Crossed Products and Matrix Algebras
Creators: name: Passer, Benjamin
Publisher: name: arXiv
Year: 2016
Subjects: subject: Operator Algebras (math.OA)
subject: FOS: Mathematics
subject: 46L85, 46L65

description: We consider a "twisted" noncommutative join procedure for unital $C^*$-algebras which admit actions by a compact abelian group $G$ and its discrete abelian dual $Γ$, so that we may investigate an analogue of Baum-Dabrowski-Hajac noncommutative Borsuk-Ulam theory in the twisted setting. Namely, under what conditions is it guaranteed that an equivariant map $ϕ$ from a unital $C^*$-algebra $A$ to the twisted join of $A$ and $C^*(Γ)$ cannot exist? This pursuit is motivated by the twisted analogues of even spheres, which admit the same $K_0$ groups as even spheres and have an analogous Borsuk-Ulam theorem that is detected by $K_0$, despite the fact that the objects are not themselves deformations of a sphere. We find multiple sufficient conditions for twisted Borsuk-Ulam theorems to hold, one of which is the addition of another equivariance condition on $ϕ$ that corresponds to the choice of twist. However, we also find multiple examples of equivariant maps $ϕ$ that exist even under fairly restrictive assumptions. Finally, we consider an extension of unital contractibility (in the sense of Dabrowski-Hajac-Neshveyev) "modulo $k$."
description: 12 pages. Version 2 implemented the following changes: stated definitions and theorems in greater generality, cleaned up proofs, and highlighted key examples (as opposed to referring to them casually in the text)
Dwarf AGNs from Variability for the Origins of Seeds (DAVOS): Intermediate-mass black hole demographics from optical synoptic surveys
Creators: name: Burke, Colin J.
name: Shen, Yue
name: Liu, Xin
name: Natarajan, Priyamvada
name: Caplar, Neven
name: Bellovary, Jillian M.
name: Wang, Z. Franklin
Publisher: name: arXiv
Year: 2022
Subjects: subject: Astrophysics of Galaxies (astro-ph.GA)
subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: FOS: Physical sciences

description: We present a phenomenological forward Monte Carlo model for forecasting the population of active galactic nuclei (AGNs) in dwarf galaxies observable via their optical variability. Our model accounts for expected changes in the spectral energy distribution of AGNs in the intermediate-mass black hole (IMBH) mass range and uses observational constraints on optical variability as a function of black hole (BH) mass to generate mock light curves. Adopting several different models for the BH occupation function, including one for off-nuclear IMBHs, we quantify differences in the predicted local AGN mass and luminosity functions in dwarf galaxies. As a result, we are able to model the variable fraction of AGNs as a function of physical host properties, such as host galaxy stellar mass, in the presence of complex selection effects. We find that our adopted occupation fractions for the "heavy" and "light" initial BH seeding scenarios can be distinguished with variability data at the $2-3 σ$ level for galaxy host stellar masses below $\sim 10^8 M_\odot$ with the Vera C. Rubin Observatory. We demonstrate the prevalence of a selection bias whereby recovered IMBH masses fall, on average, above the predicted value from the local host galaxy - BH mass scaling relation with the strength of the bias dependent on the survey sensitivity. The methodology developed in this work can be used more broadly to forecast and correct for selection effects for AGN demographic studies in synoptic surveys. Finally, we show that a targeted $\sim$ hourly cadence program over a few nights with the Rubin Observatory can provide strong constraints on IMBH masses given their expected rapid variability timescales.
description: 26 pages, 16 figures incl. 5 appendices; minor revisions and typo corrections to match published version in MNRAS
Imbert-Fedorov shift in Weyl semimetals: Dependence on monopole charge and intervalley scattering
Creators: name: Wang, Luyang
name: Jian, Shao-Kai
Publisher: name: arXiv
Year: 2017
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Imbert-Fedorov (IF) shift in optics describes the transverse shift of light beams at the reflection interface. Recently, the IF shift of Weyl fermions at the interface between Weyl semimetals (WSMs) with single monopole charge has been studied. Here, we study the IF shift at the interface between two WSMs, each of which is carrying an arbitrary integer monopole charge. We find a general relation between the monopole charges of the two WSMs and the IF shift. In particular, the IF shift is proportional to the monopole charge if both WSMs have the same one. Our results can be used to infer the topology of the materials by experimentally measuring their IF shift. Furthermore, we consider the possibility that the Weyl fermions are scattered to other Weyl cones during the reflection, which results in qualitatively different behavior of the IF shift. While we use a quantum mechanical approach to solve the problem, semiclassical equations of motion and the conservation of total angular momentum can help us intuitively interpret our results in special cases.
description: 7 pages, 3 figures, published version
Many cliques in bounded-degree hypergraphs
Creators: name: Kirsch, Rachel
name: Radcliffe, Jamie
Publisher: name: arXiv
Year: 2022
Subjects: subject: Combinatorics (math.CO)
subject: FOS: Mathematics
subject: 05C30, 05C35, 05C65, 05D05

description: Recently Chase determined the maximum possible number of cliques of size $t$ in a graph on $n$ vertices with given maximum degree. Soon afterward, Chakraborti and Chen answered the version of this question in which we ask that the graph have $m$ edges and fixed maximum degree (without imposing any constraint on the number of vertices). In this paper we address these problems on hypergraphs. For $s$-graphs with $s\ge 3$ a number of issues arise that do not appear in the graph case. For instance, for general $s$-graphs we can assign degrees to any $i$-subset of the vertex set with $1\le i\le s-1$. We establish bounds on the number of $t$-cliques in an $s$-graph $\mathcal{H}$ with $i$-degree bounded by $Δ$ in three contexts: $\mathcal{H}$ has $n$ vertices; $\mathcal{H}$ has $m$ (hyper)edges; and (generalizing the previous case) $\mathcal{H}$ has a fixed number $p$ of $u$-cliques for some $u$ with $s\le u \le t$. When $Δ$ is of a special form we characterize the extremal $s$-graphs and prove that the bounds are tight. These extremal examples are the shadows of either Steiner systems or partial Steiner systems. On the way to proving our uniqueness results, we extend results of Füredi and Griggs on uniqueness in Kruskal-Katona from the shadow case to the clique case.
description: 22 pages, 0 figures
Effective interaction in a non-Fermi liquid conductor and spin correlations in under-doped cuprates
Creators: name: Bhattacharjee, Suraka
name: Chaudhury, Ranjan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The effective interaction between the itinerant spin degrees of freedom in the paramagnetic phases of hole doped quantum Heisenberg antiferromagnets is investigated theoretically, based on the single-band t-J model on 1D lattice, at zero temperature. The effective spin-spin interaction for this model in the strong correlation limit, is studied in terms of the generalized spin stiffness constant as a function of doping concentration. The plot of this generalized spin stiffness constant against doping shows a very high value of stiffness in the vicinity of zero doping and a very sharp fall with increase in doping concentration, signifying the rapid decay of original coupling of semi-localized spins in the system. Quite interestingly, this plot also shows a maximum occurring at a finite value of doping, which strongly suggests the tendency of the itinerant spins to couple again in the unconventional paramagnetic phase. As the doping is further increased, this new coupling is also suppressed and the spin response becomes analogous to almost Pauli-like. The last two predictions of ours are quite novel and may be directly tested by independent experiments and computational techniques in future. Our results in general receive good support from other theoretical works and experimental results extracted from the chains of YBa$_2$Cu$_3$O$_{6+x}$.
description: 17 pages, 7 figures
How many perturbations break this model? Evaluating robustness beyond adversarial accuracy
Creators: name: Olivier, Raphael
name: Raj, Bhiksha
Publisher: name: arXiv
Year: 2022
Subjects: subject: Machine Learning (cs.LG)
subject: Cryptography and Security (cs.CR)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences

description: Robustness to adversarial attacks is typically evaluated with adversarial accuracy. While essential, this metric does not capture all aspects of robustness and in particular leaves out the question of how many perturbations can be found for each point. In this work, we introduce an alternative approach, adversarial sparsity, which quantifies how difficult it is to find a successful perturbation given both an input point and a constraint on the direction of the perturbation. We show that sparsity provides valuable insight into neural networks in multiple ways: for instance, it illustrates important differences between current state-of-the-art robust models them that accuracy analysis does not, and suggests approaches for improving their robustness. When applying broken defenses effective against weak attacks but not strong ones, sparsity can discriminate between the totally ineffective and the partially effective defenses. Finally, with sparsity we can measure increases in robustness that do not affect accuracy: we show for example that data augmentation can by itself increase adversarial robustness, without using adversarial training.
Poisson traces, D-modules, and symplectic resolutions
Creators: name: Etingof, Pavel
name: Schedler, Travis
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: Mathematical Physics (math-ph)
subject: Representation Theory (math.RT)
subject: Symplectic Geometry (math.SG)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 14F10, 37J05, 32S20, 53D55

description: We survey the theory of Poisson traces (or zeroth Poisson homology) developed by the authors in a series of recent papers. The goal is to understand this subtle invariant of (singular) Poisson varieties, conditions for it to be finite-dimensional, its relationship to the geometry and topology of symplectic resolutions, and its applications to quantizations. The main technique is the study of a canonical D-module on the variety. In the case the variety has finitely many symplectic leaves (such as for symplectic singularities and Hamiltonian reductions of symplectic vector spaces by reductive groups), the D-module is holonomic, and hence the space of Poisson traces is finite-dimensional. As an application, there are finitely many irreducible finite-dimensional representations of every quantization of the variety. Conjecturally, the D-module is the pushforward of the canonical D-module under every symplectic resolution of singularities, which implies that the space of Poisson traces is dual to the top cohomology of the resolution. We explain many examples where the conjecture is proved, such as symmetric powers of du Val singularities and symplectic surfaces and Slodowy slices in the nilpotent cone of a semisimple Lie algebra. We compute the D-module in the case of surfaces with isolated singularities, and show it is not always semisimple. We also explain generalizations to arbitrary Lie algebras of vector fields, connections to the Bernstein-Sato polynomial, relations to two-variable special polynomials such as Kostka polynomials and Tutte polynomials, and a conjectural relationship with deformations of symplectic resolutions. In the appendix we give a brief recollection of the theory of D-modules on singular varieties that we require.
description: 36 pages, survey article based on a series of articles by the authors. Final version, to appear in Lett. Math. Phys
Uniqueness of Kerr-Newman-de Sitter black holes with small angular momenta
Creators: name: Hintz, Peter
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Differential Geometry (math.DG)
subject: FOS: Physical sciences
subject: FOS: Mathematics
subject: Primary 83C57, Secondary 83C22

description: We show that a stationary solution of the Einstein-Maxwell equations which is close to a non-degenerate Reissner-Nordström-de Sitter solution is in fact equal to a slowly rotating Kerr-Newman-de Sitter solution. The proof uses the non-linear stability of the Kerr-Newman-de Sitter family of black holes for small angular momenta, recently established by the author, together with an extension argument for Killing vector fields. Our black hole uniqueness result only requires the solution to have high but finite regularity; in particular, we do not make any analyticity assumptions.
description: 10 pages, 1 figure. v2 is the published version, with updated bibliography
Magic State Distillation with Low Space Overhead and Optimal Asymptotic Input Count
Creators: name: Haah, Jeongwan
name: Hastings, Matthew B.
name: Poulin, D.
name: Wecker, D.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We present an infinite family of protocols to distill magic states for $T$-gates that has a low space overhead and uses an asymptotic number of input magic states to achieve a given target error that is conjectured to be optimal. The space overhead, defined as the ratio between the physical qubits to the number of output magic states, is asymptotically constant, while both the number of input magic states used per output state and the $T$-gate depth of the circuit scale linearly in the logarithm of the target error $δ$ (up to $\log \log 1/δ$). Unlike other distillation protocols, this protocol achieves this performance without concatenation and the input magic states are injected at various steps in the circuit rather than all at the start of the circuit. The protocol can be modified to distill magic states for other gates at the third level of the Clifford hierarchy, with the same asymptotic performance. The protocol relies on the construction of weakly self-dual CSS codes with many logical qubits and large distance, allowing us to implement control-SWAPs on multiple qubits. We call this code the "inner code". The control-SWAPs are then used to measure properties of the magic state and detect errors, using another code that we call the "outer code". Alternatively, we use weakly-self dual CSS codes which implement controlled Hadamards for the inner code, reducing circuit depth. We present several specific small examples of this protocol.
description: 39 pages, (v2) renamed "odd" and "even" weakly self-dual CSS codes of (v1) to "normal" and "hyperbolic" codes, respectively. (v3) published in Quantum
title: ГОРОД В КОМПЬЮТЕРНЫХ ИГРАХ: КАКИМИ ОБРАЗАМИ ОН ПИТАЕТСЯ И КАКИЕ ПИТАЕТ?
Creators: name: Очеретяный, Константин
Publisher: name: Новгородский государственный университет имени Ярослава Мудрого (НовГУ)
Year: 2022

description: Город существует по ту сторону опыта и слов — он дан в зеркале метафор, которые можно только пережить, но нельзя до конца описать или обосновать, поскольку в этой истолковательной игре они перестают быть метафорами и превращаются в понятия. В статье показано, как внимание к работе с метафорами и их когнитивными особенностями в пространстве компьютерно-игровых городов могут помочь для проектирования аналоговых городов, для создания оптимальных условий существования в них.
Incorporating Quotation and Evaluation Into Church's Type Theory
Creators: name: Farmer, William M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Logic in Computer Science (cs.LO)
subject: FOS: Computer and information sciences
subject: F.4.1; I.2.3
subject: 03B15 (Primary), 03B35 (Secondary)

description: ${\rm CTT}_{\rm qe}$ is a version of Church's type theory that includes quotation and evaluation operators that are similar to quote and eval in the Lisp programming language. With quotation and evaluation it is possible to reason in ${\rm CTT}_{\rm qe}$ about the interplay of the syntax and semantics of expressions and, as a result, to formalize syntax-based mathematical algorithms. We present the syntax and semantics of ${\rm CTT}_{\rm qe}$ as well as a proof system for ${\rm CTT}_{\rm qe}$. The proof system is shown to be sound for all formulas and complete for formulas that do not contain evaluations. We give several examples that illustrate the usefulness of having quotation and evaluation in ${\rm CTT}_{\rm qe}$.
description: 74 pages
Quantum impurity model for two-stage multipolar ordering and Fermi surface reconstruction
Creators: name: Schultz, Daniel J.
name: Han, SangEun
name: Kim, Yong Baek
Publisher: name: arXiv
Year: 2022
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: Classification and understanding of quantum phase transitions and critical phenomena in itinerant electron systems are outstanding questions in quantum materials research. Recent experiments on heavy fermion systems with higher-rank multipolar local moments provide a new platform to study such questions. In particular, experiments on $\text{Ce}_{3}\text{Pd}_{20}\text{(Si,Ge)}_{6}$ show novel quantum critical behaviors via two consecutive magnetic field-driven quantum phase transitions. At each transition, the derivative of the Hall resistivity jumps discontinuously, which was attributed to sequential Fermi surface reconstructions. Motivated by this discovery, we consider an effective quantum impurity model of itinerant electrons coupled to local dipolar, quadrupolar, and octupolar moments arising from $\text{Ce}^{3+}$ ions. Using renormalization group analyses, we demonstrate that two-stage multipolar ordering and Fermi surface reconstruction arise depending on which multipolar moments participate in the Fermi surface and which other moments are decoupled via Kondo destruction.
description: 7+16 pages, 1+11 figures, 1+4 tables; the first two authors contributed equally to this work
Hyperfine splitting in simple ions for the search of the variation of fundamental constants
Creators: name: Oreshkina, Natalia S.
name: Cavaletto, Stefano M.
name: Michel, Niklas
name: Harman, Zoltán
name: Keitel, Christoph H.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Atomic Physics (physics.atom-ph)
subject: FOS: Physical sciences

description: Numerous few-electron atomic systems are considered which can be used effectively for observing a potential variation of the fine-structure constant $α$ and the electron-proton mass ratio $m_e/m_p$. We examine optical magnetic dipole transitions between hyperfine-structure components in heavy highly charged H-like and Li-like ions with observably high sensitivity to a variation of $α$ and $m_e/m_p$. The experimental spectra of the proposed systems consist of a strong single line, which simplifies significantly the data analysis and shortens the necessary measurement time. Furthermore, we propose systems for an experimental test of the variation of quark masses and discuss the expected level of accuracy in assessing its limitations. Finally, we establish which constraints on the variation of these fundamental constants could be provided by measurements with a hyperfine-structure highly-charged-ion clock and some reference clock, showing that a significant improvement of the current limitations can be reached.
Prediction defaults for networked-guarantee loans
Creators: name: Cheng, Dawei
name: Niu, Zhibin
name: Tu, Yi
name: Zhang, Liqing
Publisher: name: arXiv
Year: 2017
Subjects: subject: Computational Engineering, Finance, and Science (cs.CE)
subject: Social and Information Networks (cs.SI)
subject: General Finance (q-fin.GN)
subject: FOS: Computer and information sciences
subject: FOS: Economics and business

description: Networked-guarantee loans may cause the systemic risk related concern of the government and banks in China. The prediction of default of enterprise loans is a typical extremely imbalanced prediction problem, and the networked-guarantee make this problem more difficult to solve. Since the guaranteed loan is a debt obligation promise, if one enterprise in the guarantee network falls into a financial crisis, the debt risk may spread like a virus across the guarantee network, even lead to a systemic financial crisis. In this paper, we propose an imbalanced network risk diffusion model to forecast the enterprise default risk in a short future. Positive weighted k-nearest neighbors (p-wkNN) algorithm is developed for the stand-alone case -- when there is no default contagious; then a data-driven default diffusion model is integrated to further improve the prediction accuracy. We perform the empirical study on a real-world three-years loan record from a major commercial bank. The results show that our proposed method outperforms conventional credit risk methods in terms of AUC. In summary, our quantitative risk evaluation model shows promising prediction performance on real-world data, which could be useful to both regulators and stakeholders.
description: 6 pages,7 figures
Calabi-Yau threefolds fibred by high rank lattice polarized K3 surfaces
Creators: name: Doran, Charles F.
name: Harder, Andrew
name: Novoseltsev, Andrey Y.
name: Thompson, Alan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14J32, 14J30, 14J28, 14D05, 14D06

description: We study threefolds fibred by K3 surfaces admitting a lattice polarization by a certain class of rank 19 lattices. We begin by showing that any family of such K3 surfaces is completely determined by a map from the base of the family to the appropriate K3 moduli space, which we call the generalized functional invariant. Then we show that if the threefold total space is a smooth Calabi-Yau, there are only finitely many possibilities for the polarizing lattice and the form of the generalized functional invariant. Finally, we construct explicit examples of Calabi-Yau threefolds realizing each case and compute their Hodge numbers.
description: 34 pages. v2: Corrected an error in Definition 2.1 that caused Theorem 2.2 to be false. Numerous other minor corrections and clarifications. v3: Further minor corrections and clarifications. Final version, accepted for publication in Math. Z
The evolving statehood before nation-formation: Qin’s wars of unification and the genesis of China’s pre-modern ethnic foundation
Creators: name: Xu, Yi
Publisher: name: Loughborough University
Year: 2022
Subjects: Other human society not elsewhere classified

description: China as a unity community, has stood the test of time for more than 2000 years, despite its periodical collapse, chaos and reunification over time. Not only has a united Chinese community survived the massive nation-building movements in the late nineteenth and the twentieth century, but it has also retained its unity after the fall of Communism in Eastern Europe and the collapse of the Soviet Union in the final decades of the twentieth century. By conducting a historiographic research on the first-ever true unification of China in 211 BC, it has been found that war had been the key trigger of China’s unification and the genesis of its pre-modern ethnic foundation in the third century BC. Not only had warfare helped establishing a truly united Chinese community for the first time in history, but it had also fostered tremendous social transformation in the Qin state (770 – 221 BC), which formed the basis for the later Qin dynasty (221 – 207 BC) – the first Chinese empire that succeeded in uniting all Chinese under a single, centralized Chinese state. Although the Qin’s wars of unification (230 – 221 BC) were the direct cause of China’s first temporary unification, Qin’s success in its attempt to unify China actually has much broader historical implications. Qin’s unification of China had been deeply rooted in the Legalist reforms by Lord Shang, which fostered Qin’s advancement in the social, political and economic spheres and had in turn resulted in Qin’s strong military competence over its six rival Chinese states. This subsequently led to Qin’s military success during its unification of China, which provides a basis for the genesis of China’s pre-modern ethnic foundation later on. However, even though the Reforms of Lord Shang, which introduced the Legalist doctrine to the Qin society, had facilitated Qin’s unification of China in the third century BC, it was unable to sustain the unity in the post-unification era. The Qin Empire only lasted for fifteen years before it fell into oblivion. This shows the fragility of Qin’ unity and the difficulty of sustaining a united but also contested Chinese community. Nevertheless, Qin’s socio-political heritage, namely the centralized socio-political system, the standardized written Chinese characters and and the Legalist doctrine, which played a key role in Qin’s unification of China, had all been inherited by succeeding Chinese dynasties and therefore facilitated the emergence of China’ pre-modern ethnic foundation in the ancient time.