cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Undersampled Phase Retrieval via Majorization-Minimization
Creators: name: Qiu, Tianyu
name: Palomar, Daniel P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: In the undersampled phase retrieval problem, the goal is to recover an $N$-dimensional complex signal $\mathbf{x}$ from only $M
Boundary and bulk notions of transport in the AdS$_3$/CFT$_2$ correspondence
Creators: name: Chen, Bowen
name: Czech, Bartlomiej
name: de Boer, Jan
name: Lamprou, Lampros
name: Wang, Zi-zhi
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: We construct operators in holographic two-dimensional conformal field theory, which act locally in the code subspace as arbitrary bulk spacelike vector fields. Key to the construction is an interplay between parallel transport in the bulk spacetime and in kinematic space. We outline challenges, which arise when the same construction is extended to timelike vector fields. We also sketch several applications, including boundary formulations of the bulk Riemann tensor, dreibein, and spin connection, as well as an application to holographic complexity.
description: 31 pages, 5 figures
Light fidelity (LI-FI) based indoor communication system
Creators: name: Aftab, Farooq
name: khan, Muhammad Nafees Ulfat
name: Ali, Shahzad
Publisher: name: arXiv
Year: 2016
Subjects: subject: Networking and Internet Architecture (cs.NI)
subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: Indoor wireless communication is an essential part of next generation wireless communication system.For an indoor communication number of users and their device are increasing very rapidly so as a result capacity of frequency spectrum to accommodate further users in future is limited and also it would be difficult for service providers to provide more user reliable and high speed communication so this short come can be solve in future by using Li-Fi based indoor communication system. Li-Fi which is an emerging branch of optical wireless communication can be useful in future as a replacement and backup of Wireless Fidelity (Wi-Fi)for indoor communication because it can provide high data rate of transmission along with high capacity to utilize more users as its spectrum bandwidth is much broader than the radio spectrum. In this paper we will look at the different aspects of the Li-Fi based indoor communication system,summarizes some of the research conducted so far and we will also proposed a Li-Fi based communication model keeping in mind coverage area for multiple user and evaluate its performance under different scenarios .
description: 11 Pages, 7 figures, May 2016, International Journal of Computer Networks & Communications (IJCNC)
Terabyte-scale supervised 3D training and benchmarking dataset of the mouse kidney
Creators: name: Kuo, Willy
name: Rossinelli, Diego
name: Schulz, Georg
name: Wenger, Roland H.
name: Hieber, Simone
name: Müller, Bert
name: Kurtcuoglu, Vartan
Publisher: name: arXiv
Year: 2021
Subjects: subject: Computer Vision and Pattern Recognition (cs.CV)
subject: Medical Physics (physics.med-ph)
subject: Tissues and Organs (q-bio.TO)
subject: FOS: Computer and information sciences
subject: FOS: Physical sciences
subject: FOS: Biological sciences

description: The performance of machine learning algorithms, when used for segmenting 3D biomedical images, does not reach the level expected based on results achieved with 2D photos. This may be explained by the comparative lack of high-volume, high-quality training datasets, which require state-of-the-art imaging facilities, domain experts for annotation and large computational and personal resources. The HR-Kidney dataset presented in this work bridges this gap by providing 1.7 TB of artefact-corrected synchrotron radiation-based X-ray phase-contrast microtomography images of whole mouse kidneys and validated segmentations of 33 729 glomeruli, which corresponds to a one to two orders of magnitude increase over currently available biomedical datasets. The image sets also contain the underlying raw data, threshold- and morphology-based semi-automatic segmentations of renal vasculature and uriniferous tubules, as well as true 3D manual annotations. We therewith provide a broad basis for the scientific community to build upon and expand in the fields of image processing, data augmentation and machine learning, in particular unsupervised and semi-supervised learning investigations, as well as transfer learning and generative adversarial networks.
A two-sided academic landscape: portrait of highly-cited documents in Google Scholar (1950-2013)
Creators: name: Martin-Martin, Alberto
name: Orduna-Malea, Enrique
name: Ayllon, Juan M.
name: Lopez-Cozar, Emilio Delgado
Publisher: name: arXiv
Year: 2016
Subjects: subject: Digital Libraries (cs.DL)
subject: FOS: Computer and information sciences

description: The main objective of this paper is to identify the set of highly-cited documents in Google Scholar and to define their core characteristics (document types, language, free availability, source providers, and number of versions), under the hypothesis that the wide coverage of this search engine may provide a different portrait about this document set respect to that offered by the traditional bibliographic databases. To do this, a query per year was carried out from 1950 to 2013 identifying the top 1,000 documents retrieved from Google Scholar and obtaining a final sample of 64,000 documents, of which 40% provided a free full-text link. The results obtained show that the average highly-cited document is a journal article or a book (62% of the top 1% most cited documents of the sample), written in English (92.5% of all documents) and available online in PDF format (86.0% of all documents). Yet, the existence of errors especially when detecting duplicates and linking cites properly must be pointed out. The fact of managing with highly cited papers, however, minimizes the effects of these limitations. Given the high presence of books, and to a lesser extend of other document types (such as proceedings or reports), the research concludes that Google Scholar data offer an original and different vision of the most influential academic documents (measured from the perspective of their citation count), a set composed not only by strictly scientific material (journal articles) but academic in its broad sense
description: 26 pages, 5 tables, 10 figures
Theory of electron-plasmon coupling in semiconductors
Creators: name: Caruso, Fabio
name: Giustino, Feliciano
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: The ability to manipulate plasmons is driving new developments in electronics, optics, sensing, energy, and medicine. Despite the massive momentum of experimental research in this direction, a predictive quantum-mechanical framework for describing electron-plasmon interactions in real materials is still missing. Here, starting from a many-body Green's function approach, we develop an ab initio approach for investigating electron-plasmon coupling in solids. As a first demonstration of this methodology, we show that electron-plasmon scattering is the primary mechanism for the cooling of hot carriers in doped silicon, it is key to explain measured electron mobilities at high doping, and it leads to a quantum zero-point renormalization of the band gap in agreement with experiment.
The Cosmic Large-Scale Structure in X-rays (CLASSIX) Cluster Survey I: Probing galaxy cluster magnetic fields with line of sight rotation measures
Creators: name: Boehringer, Hans
name: Chon, Gayoung
name: Kronberg, Philipp P.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: To search for a signature of an intracluster magnetic field, we compare measurements of Faraday rotation of polarised extragalactic radio sources in the line of sight of galaxy clusters with those outside. We correlated a catalogue of 1383 rotation measures (RM) of extragalactic polarised radio sources with X-ray luminous galaxy clusters from the CLASSIX survey (combining REFLEX II and NORAS II). We compared the RM in the line of sight of clusters within their projected radii of r_500 with those outside and found a significant excess of the dispersion of the RM in the cluster regions. Since the observed RM is the result of Faraday rotation in several presumably uncorrelated magnetised cells of the intracluster medium, the observations correspond to quantities averaged over several magnetic field directions and strengths. Therefore the interesting quantity is the standard deviation of the RM for an ensemble of clusters. We found a standard deviation of the RM inside r_500 of about 120 +- 21 rad m^-2. This compares to about 56 +- 8 rad m^-2 outside. We show that the most X-ray luminous and thus most massive clusters contribute most to the observed excess RM. Modelling the electron density distribution in the intracluster medium with a self-similar model, we found that the dispersion of the RM increases with the column density, and we deduce a magnetic field value of about 2 - 6 (l/10kpc)^-1/2 microG assuming a constant magnetic field strength, where l is the size of the coherently magnetised intracluster medium cells. This magnetic field energy density amounts to a few percent of the average thermal energy density in clusters. When we assumed the magnetic energy density to be a constant fraction of the thermal energy density, we deduced a slightly lower value for this fraction of 3 - 10 (l/10kpc)^-1/2 per mille.
description: 7 pages, 6 figures, in press, Astronomy and Astrophysics, 2016
Single active particle in a harmonic potential: non-existence of the Jarzynski relation
Creators: name: Szamel, Grzegorz
Publisher: name: arXiv
Year: 2022
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Soft Condensed Matter (cond-mat.soft)
subject: FOS: Physical sciences

description: The interest in active matter stimulates the need to generalize thermodynamic description and relations to active matter systems, which are intrinsically out of equilibrium. One important example is the Jarzynski relation, which links the exponential average of work done in an arbitrary process connecting two equilibrium states with the difference of the free energies of these states. Using a simple model system, a single thermal active Ornstein-Uhlenbeck particle in a harmonic potential, we show that if the standard stochastic thermodynamics definition of work is used, the Jarzynski relation is not generally valid for processes between stationary states of active matter systems.
description: 8 pages
Intermediary-led Participation in Regeneration: Governing and Networking Communities in Post- Developmental Urbanism - A Study of Seoul
Creators: name: Kim, Kon
Publisher: name: University of Westminster
Year: 2021

description: This thesis investigates the dynamics of community participation led by intermediary organisations in the urban regeneration of South Korea. Since the 2010s, the Korean government has tried to institutionalise community participation in its planning system by devising new partnerships between the state, citizens, and intermediary organisations. Intermediary organisations act as brokers to promote community participation throughout the regeneration process. Such intermediary intervention is a distinctive part of the recent planning system, which forms the basis for alternative approaches to past state-led or market-driven urban development in Korea. Despite its importance, the dynamics behind intermediary intervention have rarely been addressed. In particular, little attention has been paid to power relationships and social networks that are constructed through intermediary intervention, which can provide an additional insight into the fundamental nature of community participation in Korea’s planning system. Using research data collected mainly from fieldwork in Korea, this study explores the dynamics of community participation, with a focus on the governance arrangements and network structures that have evolved through intermediary intervention. This thesis argues that intermediary intervention remains largely under state control, which restricts the financial resources and legal rights of intermediaries. While intermediary intervention has been managed by professional firms, its transformative potential for community empowerment has been undermined due to new rules and norms armed with expertise and professionalism, which were preferred by the state. On the other hand, more autonomous intermediary intervention has contributed to community empowerment but gained less institutional support, and this has enabled the state to maintain control over community participation, albeit in indirect ways. This thesis concludes that new challenges facing community participation emerging from intermediary intervention can be understood as a developmental legacy of the interventionist state in the post-developmental context in Korea. At the same time, it highlights that intermediary intervention can serve as a long-term platform to address such new challenges by constantly attempting to communicate with the citizens and negotiate with the state throughout the regeneration process. Investigating the dynamics of community participation also provides an opportunity to expand the empirical basis for a wider discourse on post-developmental urbanism in Korea and East Asia.
A bifurcation analysis for the Lugiato-Lefever equation
Creators: name: Godey, Cyril
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35B32, 35Q55, 37G05

description: The Lugiato-Lefever equation is a cubic nonlinear Schrödinger equation, including damping, detuning and driving, which arises as a model in nonlinear optics. We study the existence of stationary waves which are found as solutions of a four-dimensional reversible dynamical system in which the evolutionary variable is the space variable. Relying upon tools from bifurcation theory and normal forms theory, we discuss the codimension 1 bifurcations. We prove the existence of various types of steady solutions, including spatially localized, periodic, or quasi-periodic solutions.
Precision Studies of QCD in the Low Energy Domain of the EIC
Creators: name: Burkert, V.
name: Elouadrhiri, L.
name: Afanasev, A.
name: Arrington, J.
name: Contalbrigo, M.
name: Cosyn, W.
name: Deshpande, A.
name: Glazier, D.
name: Ji, X.
name: Liuti, S.
name: Oh, Y.
name: Richards, D.
name: Satogata, T.
name: Vossen, A.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Nuclear Experiment (nucl-ex)
subject: High Energy Physics - Experiment (hep-ex)
subject: High Energy Physics - Lattice (hep-lat)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: The manuscript focuses on the high impact science of the EIC with objective to identify a portion of the science program for QCD precision studies that requires or greatly benefits from high luminosity and low center-of-mass energies. The science topics include (1) Generalized Parton Distributions, 3D imagining and mechanical properties of the nucleon (2) mass and spin of the nucleon (3) Momentum dependence of the nucleon in semi-inclusive deep inelastic scattering (4) Exotic meson spectroscopy (5) Science highlights of nuclei (6) Precision studies of Lattice QCD in the EIC era (7) Science of far-forward particle detection (8) Radiative effects and corrections (9) Artificial Intelligence (10) EIC interaction regions for high impact science program with discovery potential. This paper documents the scientific basis for supporting such a program and helps to define the path toward the realization of the second EIC interaction region.
description: 103 pages,47 figures
Crossover scaling of apparent first-order wetting in two dimensional systems with short-ranged forces
Creators: name: Parry, Andrew O.
name: Malijevský, Alexandr
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: Recent analyses of wetting in the semi-infinite two dimensional Ising model, extended to include both a surface coupling enhancement and a surface field, have shown that the wetting transition may be effectively first-order and that surprisingly the surface susceptibility develops a divergence described by an anomalous exponent with value $γ_{11}^{\rm eff}=\frac{3}{2}$. We reproduce these results using an interfacial Hamiltonian model making connection with previous studies of two dimensional wetting and show that they follow from the simple crossover scaling of the singular contribution to the surface free-energy which describes the change from apparent first-order to continuous (critical) wetting due to interfacial tunnelling. The crossover scaling functions are calculated explicitly within both the strong-fluctuation and intermediate-fluctuation regimes and determine uniquely and more generally the value of $γ_{11}^{\rm eff}$ which is non-universal for the latter regime. The location and the rounding of a line of pseudo pre-wetting transitions occurring above the wetting temperature and off bulk coexistence, together with the crossover scaling of the parallel correlation length, is also discussed in detail.
Search for Compact Stellar Groups in the Vicinity of IRAS Sources
Creators: name: Azatyan, N. M.
name: Nikoghosyan, E. H.
name: Khachatryan, K. G.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Astrophysics of Galaxies (astro-ph.GA)
subject: FOS: Physical sciences

description: The results of a search for compact clusters in the vicinity of 19 IRAS sources based on data from the GPS UKIDSS and Spitzer GLIMPSE surveys are presented. Overall, clusters have been identified in 15 regions. Clusters are identified for the first time in 4 regions (IRAS 18151-1208, IRAS 18316-0602, 18517+0437, 19110+1045). In 5 regions (IRAS 05168+3634, 05358+3543, IRAS 18507+0121, IRAS 20188+3928, IRAS 20198+3716) the compact groups we have identified are substructures within more extended clusters. The radii of the identified groups and the surface star density are widely scattered with ranges of 0.3-2.7 pc and 4-1360 stars/pc^2, respectively. In 11 of the clusters, the IRAS sources are associated with a pair or even a group of YSOs. The groups identified in the near IR include representatives of a later evolutionary class II among the stellar objects associated with the IRAS sources.
description: 18 pages, 3 figures, 2 tables
Web Appendixes for "Me and my AI: Exploring the effects of consumer self-construal and AI-based experience on avoiding similarity and willingness to pay"
Creators: name: Loureiro, Sandra Maria Correia
name: Jiménez-Barreto, Jano
name: Bilro, Ricardo
name: Romero, Jaime
Publisher: name: figshare
Year: 2023
Subjects: classificationCode: 350607
subject: Marketing technology

description: These web appendices are part of the article "Me and my AI: Exploring the effects of consumer self-construal and AI-based experience on avoiding similarity and willingness to pay" published on 'Psychology & Marketing' and comprise Appendix A to Appendix K.
Building trust in cross-cultural relationships: Active trust through culture mobilisation in Finnish-Indian project teams
Creators: name: Hankimaa, Anna
Publisher: name: University of Westminster
Year: 2021

description: This thesis examines trust building in Finnish-Indian distributed teams engaged in knowledge-intensive project work. To understand how actors build trust in the context of cultural distance and virtual collaboration, dynamic approaches to trust building and culture were adopted. The data were collected through interviews and observations in both geographical locations. In distributed project teams, static and slowly evolving trust creation models are not sufficient in explaining the ways trust is built to meet the needs of temporal project teams working distantly in a cross-cultural environment. Thus, this study suggests active trust as a solution in this challenging context of trust creation and places the main emphasis on the role of an active trustor. In doing so, this research challenges the static and passive trust models where trust development is focused on the trustee and their trustworthiness. Moreover, the study challenges the static culture approaches and adopts a dynamic mosaic perspective to culture as a collection of various cultural identities and elements that are used as resources. This allows for the examination of the agentic view of culture mobilisation. The findings illustrate how trusting parties are capable of mobilising various cultural elements and engage in purposeful trust-building practices to lessen the vulnerability caused by the unfamiliarity due to cultural differences and virtual communication. The agency in constructing actions to build trust is a central feature of collaborators who are successful in active trust building. Furthermore, researching the mobilisation of cultural elements in trust building revealed that the collaborators were not only drawing on existing cultural similarities but also engaged in a process of adjusting and adopting new cultural elements. The co-created third culture acted as the strongest nominator for active trust development in Finnish-Indian project teams. This thesis contributes to business practitioners working in the context of global teams where practices of active trust are needed to allow collaboration on complex and novel tasks that require efficient knowledge transfer. The findings guide team members to actively invest in the co-creation of shared culture elements and proactively shape the conditions for trusting.
Noether identities in gravity theories with nondynamical backgrounds and explicit spacetime symmetry breaking
Creators: name: Bluhm, Robert
name: Sehic, Amar
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: Gravitational effective field theories with nondynamical backgrounds explicitly break diffeomorphism and local Lorentz invariance. At the same time, to maintain observer independence the action describing these theories is required to be mathematically invariant under general coordinate transformations and changes of local Lorentz bases. These opposing effects of having broken spacetime symmetries but invariance under mathematical observer transformations can result in theoretical inconsistency unless certain conditions hold. The consistency constraints that must hold originate from Noether identities associated with the mathematical observer invariances in the action. These identities are examined in detail and are used to investigate gravity theories with nondynamical backgrounds, including when a Stückelberg approach is used. Specific examples include gravity theories with fixed scalar or tensor backgrounds, Einstein-Maxwell theory with a fixed external current, and massive gravity.
description: 13 pages
Canards in a bottleneck
Creators: name: Iuorio, Annalisa
name: Jankowiak, Gaspard
name: Szmolyan, Peter
name: Wolfram, Marie-Therese
Publisher: name: arXiv
Year: 2022
Subjects: subject: Dynamical Systems (math.DS)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 34B16, 34E13, 34E15 (Primary), 35B25, 35B40, 65L11, 76A30 (Secondary)

description: In this paper we investigate the stationary profiles of a nonlinear Fokker-Planck equation with small diffusion and nonlinear in- and outflow boundary conditions. We consider corridors with a bottleneck whose width has a global nondegenerate minimum in the interior. In the small diffusion limit the profiles are obtained constructively by using methods from geometric singular perturbation theory (GSPT). We identify three main types of profiles corresponding to: (i) high density in the domain and a boundary layer at the entrance, (ii) low density in the domain and a boundary layer at the exit, and (iii) transitions from high density to low density inside the bottleneck with boundary layers at the entrance and exit. Interestingly, solutions of the last type involve canard solutions generated at the narrowest point of the bottleneck. We obtain a detailed bifurcation diagram of these solutions in terms of the in- and outflow rates. The analytic results based on GSPT are further corroborated by computational experiments investigating corridors with bottlenecks of variable width.
description: arXiv admin note: text overlap with arXiv:2010.14424
Recurrence Relations of the Multi-Indexed Orthogonal Polynomials IV : closure relations and creation/annihilation operators
Creators: name: Odake, Satoru
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: High Energy Physics - Theory (hep-th)
subject: Classical Analysis and ODEs (math.CA)
subject: Exactly Solvable and Integrable Systems (nlin.SI)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: We consider the exactly solvable quantum mechanical systems whose eigenfunctions are described by the multi-indexed orthogonal polynomials of Laguerre, Jacobi, Wilson and Askey-Wilson types. Corresponding to the recurrence relations with constant coefficients for the $M$-indexed orthogonal polynomials, it is expected that the systems satisfy the generalized closure relations. In fact we can verify this statement for small $M$ examples. The generalized closure relation gives the exact Heisenberg operator solution of a certain operator, from which the creation and annihilation operators of the system are obtained.
description: 33 pages
Imaging Electron Motion in Graphene
Creators: name: Bhandari, Sagar
name: Westervelt, Robert M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Research in semiconductor physics has advanced to the study of two-dimensional (2D) materials where the surface controls electronic transport. A scanning probe microscope (SPM) is an ideal tool to image electronic motion in these devices by using the SPM tip as a scanning gate. In prior work for a two dimensional electron gas (2DEG) in a GaAs/AlGaAs heterostructure, a number of phenomena were imaged, including electron flow from a quantum point contact, and tuning of a few electron quantum dot. This approach was also used to study InAs quantum dots grown in a InAs/InP nanowire heterostructure. New two-dimensional materials such as graphene show great promise for fundamental research and applications. We have extended or prior work to image the motion of electrons along cyclotron orbits in single atomic layer graphene passing from one point contact to a second point contact on the first magnetic focusing peak in graphene. The charged SPM tip defects electrons passing from one contact to the other, changing the conductance. A plot of the change in conductance vs. tip position presents an image of electron flow. A low temperature Scanning Capacitance Microscope (SCM) with a sensitive charge preamplifier located near the SPM tip achieves a charge noise level 0.13 e/Hz1/2 with high spatial resolution 100 nm, which promises to be useful to study electronic behavior in nanoscale devices.
description: 11 pages, 8 figures, Review on Scanning Probe Microscope Imaging Technique
Speedup of lexicographic optimization by superiorization and its applications to cancer radiotherapy treatment
Creators: name: Bonacker, Esther
name: Gibali, Aviv
name: Küfer, Karl-Heinz
name: Süss, and Philipp
Publisher: name: arXiv
Year: 2016
Subjects: subject: Optimization and Control (math.OC)
subject: FOS: Mathematics
subject: 65K10, 65K15, 90C25, 90C90

description: Multicriteria optimization problems occur in many real life applications, for example in cancer radiotherapy treatment and in particular in intensity modulated radiation therapy (IMRT). In this work we focus on optimization problems with multiple objectives that are ranked according to their importance. We solve these problems numerically by combining lexicographic optimization with our recently proposed level set scheme, which yields a sequence of auxiliary convex feasibility problems; solved here via projection methods. The projection enables us to combine the newly introduced superiorization methodology with multicriteria optimization methods to speed up computation while guaranteeing convergence of the optimization. We demonstrate our scheme with a simple 2D academic example (used in the literature) and also present results from calculations on four real head neck cases in IMRT (Radiation Oncology of the Ludwig-Maximilians University, Munich, Germany) for two different choices of superiorization parameter sets suited to yield fast convergence for each case individually or robust behavior for all four cases.
description: arXiv admin note: text overlap with arXiv:1406.6143 by other authors
QED Fermions in a noisy magnetic field background
Creators: name: Castaño-Yepes, Jorge David
name: Loewe, Marcelo
name: Muñoz, Enrique
name: Rojas, Juan C.
name: Zamora, Renato
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We consider the effects of a noisy magnetic field background over the fermion propagator in QED, as an approximation to the spatial inhomogeneities that would naturally arise in certain physical scenarios, such as heavy-ion collisions or the quark-gluon plasma in the early stages of the evolution of the Universe. We considered a classical, finite and uniform average magnetic field background $\langle\mathbf{B}(\mathbf{x})\rangle = \mathbf{B}$, subject to white-noise spatial fluctuations with auto-correlation of magnitude $Δ_B$. By means of the Schwinger representation of the propagator in the average magnetic field as a reference system, we used the replica formalism to study the effects of the magnetic noise in the form of renormalized quasi-particle parameters, leading to an effective charge and an effective refraction index, that depend not only on the energy scale, as usual, but also on the magnitude of the noise $Δ_B$ and the average field $\mathbf{B}$.
On the Structure of Equilibrium Strategies in Dynamic Gaussian Signaling Games
Creators: name: Sayin, Muhammed
name: Akyol, Emrah
name: Basar, Tamer
Publisher: name: arXiv
Year: 2016
Subjects: subject: Systems and Control (eess.SY)
subject: Computer Science and Game Theory (cs.GT)
subject: Information Theory (cs.IT)
subject: FOS: Electrical engineering, electronic engineering, information engineering
subject: FOS: Computer and information sciences

description: This paper analyzes a finite horizon dynamic signaling game motivated by the well-known strategic information transmission problems in economics. The mathematical model involves information transmission between two agents, a sender who observes two Gaussian processes, state and bias, and a receiver who takes an action based on the received message from the sender. The players incur quadratic instantaneous costs as functions of the state, bias and action variables. Our particular focus is on the Stackelberg equilibrium, which corresponds to information disclosure and Bayesian persuasion problems in economics. Prior work solved the static game, and showed that the Stackelberg equilibrium is achieved by pure strategies that are linear functions of the state and the bias variables. The main focus of this work is on the dynamic (multi-stage) setting, where we show that the existence of a pure strategy Stackelberg equilibrium, within the set of linear strategies, depends on the problem parameters. Surprisingly, for most problem parameters, a pure linear strategy does not achieve the Stackelberg equilibrium which implies the existence of a trade-off between exploiting and revealing information, which was also encountered in several other asymmetric information games.
description: will appear in IEEE Multi-Conference on Systems and Control 2016
Distribution of class numbers in continued fraction families of real quadratic fields
Creators: name: Dahl, Alexander
name: Kala, Vítězslav
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11R11, 11M20, 11A55

description: We construct a random model to study the distribution of class numbers in special families of real quadratic fields $\mathbb Q(\sqrt d)$ arising from continued fractions. These families are obtained by considering periodic continued fraction expansions of the form $\sqrt {D(n)}=[f(n), [u_1, u_2, \dots, u_{s-1}, 2f(n)]]$ with fixed coefficients $u_1, \dots, u_{s-1}$ and generalize well-known families such as Chowla's $4n^2+1$, for which analogous results were recently proved by Dahl and Lamzouri.
description: 20 pages
Dilaton at the LHC: Complementary Probe of Composite Higgs
Creators: name: Bruggisser, Sebastian
name: von Harling, Benedict
name: Matsedonskyi, Oleksii
name: Servant, Geraldine
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: FOS: Physical sciences

description: The dilaton is predicted in various extensions of the standard model containing sectors with an approximate spontaneously-broken conformal invariance. As a Goldstone boson of a spontaneously broken symmetry, the dilaton can naturally be one of the lightest new physics particles, and therefore may be the first new physics imprint observed in collider experiments. In particular, it can arise in composite Higgs models which are often assumed to have approximate conformal invariance in the UV. The dilaton is then a composite state, generated by the same sector that produces the Higgs. We continue the exploration of composite dilaton signatures at the LHC, using the latest experimental data and analysing the future detection prospects. We elaborate on the connection of the dilaton properties with the properties of the Higgs potential, clarifying in particular the relation between the scale relevant for electroweak fine tuning and the scale controlling the dilaton couplings. This relation is then used to derive the experimental sensitivity to the dilaton in natural composite Higgs scenarios, which reaches ~3 TeV in dilaton mass for generic parameter choices. At the same time, we show that dilaton searches are a complementary direction to probe Higgs boson compositeness, with the sensitivity comparable or exceeding that of Higgs coupling measurements.
description: 26 pages, 18 figures; v2: two plots, comments and references added, JHEP version
Intergrated Data Workflow using HELIPORT at TELBE
Creators: name: Lokamani, Mani
Publisher: name: Zenodo
Year: 2022
Subjects: data management
terahertz
High-Field High-Repetition-Rate
workflow
metadata

description: At the High-Field High-Repetition-Rate Terahertz facility @ ELBE (TELBE), ultrafast terahertz-induced dynamics can be probed in various states of matter with highest precision. The TELBE sources offer both, stable and tunable narrowband THz radiation with pulse energies of several microjoules at high repetition rates and a synchronized coherent diffraction radiator,that provides broadband single-cycle pulses. The measurements at TELBE are data intensive, which can be as high as 20GB per experiment, that can lasts up to several minutes. As a result, the current data aquisition and data analysis stages are decoupled, where in the first step the primary data is processed and stored at HZDR and in a later step, restricted data access is made available to the user for post-processing. In this poster contribution, we present an integrated workflow for post-processing of the experimental data at TELBE with in-built exchange of metadata between the experiment control software LabView and the workflow execution engine UNICORE. We also present the guidance system HELIPORT which manages the metadata of the associated project proposal and job information from UNICORE, and integrates with the electronic lab notebook (MediaWiki), providing a user-friendly interface for monitoring the actively running experiments at TELBE.
Evidence of a decreasing trend for the Hubble constant
Creators: name: Jia, X. D.
name: Hu, J. P.
name: Wang, F. Y.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The current discrepancy between the Hubble constant $H_0$ derived from the local distance ladder and from the cosmic microwave background is one of the most crucial issues in cosmology, as it possibly indicates unknown systematics or new physics. Here we present a novel non-parametric method to estimate Hubble constant as a function of redshift. We establish independent estimates of the evolution of Hubble constant by diagonalizing the covariance matrix. From type Ia supernovae and the observed Hubble parameter data, a decreasing trend of Hubble constant with a significance of 5.6$σ$ confidence level is found. At low redshift, its value is dramatically consistent with that measured from the local distance ladder, and it drops to the value measured from the cosmic microwave background at high redshift. Our results can relieve the Hubble tension, and prefer the late-time solutions of it, especially the new physics.
description: 10 pages, 6 figures, 5 tables, match the proofread version
Polarons and bipolarons in a two-dimensional square lattice
Creators: name: Ding, Shanshan
name: Domínguez-Castro, G. A.
name: Julku, Aleksi
name: Camacho-Guardian, Arturo
name: Bruun, Georg M.
Publisher: name: arXiv
Year: 2022
Subjects: subject: Quantum Gases (cond-mat.quant-gas)
subject: FOS: Physical sciences

description: Quasiparticles and their interactions are a key part of our understanding of quantum many-body systems. Quantum simulation experiments with cold atoms have in recent years advanced our understanding of isolated quasiparticles, but so far they have provided limited information regarding their interactions and possible bound states. Here, we show how exploring mobile impurities immersed in a Bose-Einstein condensate (BEC) in a two-dimensional lattice can address this problem. First, the spectral properties of individual impurities are examined, and in addition to the attractive and repulsive polarons known from continuum gases, we identify a new kind of quasiparticle stable for repulsive boson-impurity interactions. The spatial properties of polarons are calculated showing that there is an increased density of bosons at the site of the impurity both for repulsive and attractive interactions. We then derive an effective Schrödinger equation describing two polarons interacting via the exchange of density oscillations in the BEC, which takes into account strong impurity-boson two-body correlations. Using this, we show that the attractive nature of the effective interaction between two polarons combined with the two-dimensionality of the lattice leads to the formation of bound states -- i.e. bipolarons. The wave functions of the bipolarons are examined showing that the ground state is symmetric under particle exchange and therefore relevant for bosonic impurities, whereas the first excited state is doubly degenerate and odd under particle exchange making it relevant for fermionic impurities. Our results show that quantum gas microscopy in optical lattices is a promising platform to explore the spatial properties of polarons as well as to finally observe the elusive bipolarons.
description: Submission to SciPost
Absolute negative mobility of an active tracer in a crowded environment
Creators: name: Rizkallah, Pierre
name: Sarracino, Alessandro
name: Bénichou, Olivier
name: Illien, Pierre
Publisher: name: arXiv
Year: 2022
Subjects: subject: Soft Condensed Matter (cond-mat.soft)
subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: Absolute negative mobility (ANM) refers to the situation where the average velocity of a driven tracer is opposite to the direction of the driving force. This effect was evidenced in different models of nonequilibrium transport in complex environments, whose description remains effective. Here, we provide a microscopic theory for this phenomenon. We show that it emerges in the model of an active tracer particle submitted to an external force, and evolving on a discrete lattice populated with mobile passive crowders. Resorting to a decoupling approximation, we compute analytically the velocity of the tracer particle as a function of the different parameters of the system, and confront our results to numerical simulations. We determine the range of parameters where ANM can be observed, characterize the response of the environment to the displacement of the tracer, and clarify the mechanism underlying ANM and its relationship with negative differential mobility (another hallmark of driven systems far from the linear response).
Comments on 1+1d QCD with heavy adjoint quarks
Creators: name: Asrat, Meseret
Publisher: name: arXiv
Year: 2022
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: In this paper, we determine at weak coupling the non-relativistic $n$-body Schrödinger equation that describes the low-lying color singlet bound states of two dimensional adjoint $QCD$ with heavy quarks. In the case of three adjoint quarks, we show that the three-body equation reduces equivalently to the Schrödinger equation that describes a point electric dipole in an electric field in a plane angular sector. We conjecture that the three-body problem is solvable. The eigenstates are given in terms of the triconfluent Heun functions. Our conjecture implies that a bound state of three adjoint quarks is described by a particle confined in a two dimensional Cornell potential. We expect the $n$-parton problem also to be solvable in a similar fashion.
description: v3. 36 pages; references added, comments added, typos corrected
Detection of separatrices and chaotic seas based on orbit amplitudes
Creators: name: Daquin, Jerome
name: Charalambous, Carolina
Publisher: name: arXiv
Year: 2022
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Instrumentation and Methods for Astrophysics (astro-ph.IM)
subject: Chaotic Dynamics (nlin.CD)
subject: FOS: Physical sciences

description: The Maximum Eccentricity Method (MEM) is a standard tool for the analysis of planetary systems and their stability. The method amounts to estimating the maximal stretch of orbits over sampled domains of initial conditions. The present paper leverages on the MEM to introduce a sharp detector of separatrices and chaotic seas. After introducing the MEM analogue for nearly-integrable action-angle Hamiltonians, i.e., diameters, we use low-dimensional dynamical systems with multi-resonant modes and junctions, supporting chaotic motions, to recognise the drivers of the diameter metric. Once this is appreciated, we present a second-derivative based index measuring the regularity of this application. This quantity turns to be a sensitive and robust indicator to detect separatrices, resonant webs and chaotic seas. We discuss practical applications of this framework in the context of $N$-body simulations for the planetary case affected by mean-motion resonances, and demonstrate the ability of the index to distinguish minute structures of the phase space, otherwise undetected with the original MEM.
description: Under review at Celestial Mechanics and Dynamical Astronomy. 8 Figures, 59 references, 17 pages. Comments and feedback welcome
Solar Energetic Particle Event Associated with the 2012 July 23 Extreme Solar Storm
Creators: name: Zhu, Bei
name: Liu, Ying D.
name: Luhmann, Janet G.
name: Hu, Huidong
name: Wang, Rui
name: Yang, Zhongwei
Publisher: name: arXiv
Year: 2016
Subjects: subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: Space Physics (physics.space-ph)
subject: FOS: Physical sciences

description: We study the solar energetic particle (SEP) event associated with the 2012 July 23 extreme solar storm, for which STEREO and the spacecraft at L1 provide multi-point remote sensing and in situ observations. The extreme solar storm, with a superfast shock and extremely enhanced ejecta magnetic fields observed near 1 AU at STEREO A, was caused by the combination of successive coronal mass ejections (CMEs). Meanwhile, energetic particles were observed by STEREO and near-Earth spacecraft such as ACE and SOHO, suggestive of a wide longitudinal spread of the particles at 1 AU. Combining the SEP observations with in situ plasma and magnetic field measurements we investigate the longitudinal distribution of the SEP event in connection with the associated shock and CMEs. Our results underscore the complex magnetic configuration of the inner heliosphere formed by solar eruptions. The examinations of particle intensities, proton anisotropy distributions, element abundance ratios, magnetic connectivity and spectra also give important clues for the particle acceleration, transport and distribution.
description: accepted for publication in ApJ
Asymptotic analysis on charging dynamics for stack-electrode model of supercapacitors
Creators: name: Ji, Lijie
name: Xu, Zhenli
name: Zhou, Shenggao
Publisher: name: arXiv
Year: 2022
Subjects: subject: Numerical Analysis (math.NA)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: Supercapacitors are promising electrochemical energy storage devices due to their prominent performance in rapid charging/discharging rates, long cycle life, stability, etc. Experimental measurement and theoretical prediction on charging timescale for supercapacitors often have large difference. This work develops a matched asymptotic expansion method to derive the charging dynamics of supercapacitors with porous electrodes, in which the supercapacitors are described by the stack-electrode model. Coupling leading-order solutions between every two stacks by continuity of ionic concentration and fluxes leads to an ODE system, which is a generalized equivalent circuit model for zeta potentials, with the potential-dependent nonlinear capacitance and resistance determined by physical parameters of electrolytes, e.g., specific counterion valences for asymmetric electrolytes. Linearized stability analysis on the ODE system after projection is developed to theoretically characterize the charging timescale. The derived asymptotic solutions are numerically verified. Further numerical investigations on the biexponential charging timescales demonstrate that the proposed generalized equivalent circuit model, as well as companion linearized stability analysis, can faithfully capture the charging dynamics of symmetric/asymmetric electrolytes in supercapacitors with porous electrodes.
description: 26 pages, 6 figures
Pressure Driven Phase Transition in 1T-TiSe$_2$ , a MOIPT+DMFT Study
Creators: name: Koley, S
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The nature of unconventional superconductivity associated with charge density wave order in transition metal dichalcogenides is currently a debated issue. Starting from a normal state elec- tronic structure followed by a charge ordered state how superconductivity in 1T-TiSe 2 arises with applied pressure is still under research. A preformed excitonic liquid driven ordered state mediated superconductivity is found in broad class of TMD on the border of CDW. Using dynamical mean field theory with input from noninteracting band structure calculation, I show a superconducting phase appears near about 2 GPa pressure at a temperature of 2 K and this region persists upto 4 GPa Pressure.
description: 7 Pages, 6 Figures