cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
On validity of the quasi-static approximation in scalar-tensor theories
Creators: name: Mirpoorian, Seyed Hamidreza
name: Wang, Zhuangfei
name: Pogosian, Levon
Publisher: name: arXiv
Year: 2023
Subjects: subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: The discovery of cosmic acceleration motivated extensive studies of dynamical dark energy and modified gravity models. Of particular interest are the scalar-tensor theories, with a scalar field dark energy non-minimally coupled to matter. Cosmological constraints on these models often employ the quasi-static approximation (QSA), in which the dynamics of the scalar field perturbations is proportional to the perturbation in the matter density. Using the QSA simplifies the physical interpretation of the phenomenology of scalar-tensor theories, and results in substantial savings of computing time when deriving parameter constraints. Focusing on the symmetron model, which is a well-motivated scalar-tensor theory with a screening mechanism, we compare the exact solution of the linearly perturbed field equations to those obtained under the QSA and identify the range of the model parameters for which the QSA is valid. We find that the evolution of background scalar field is most important, namely, whether it is dominated by the Hubble friction or the scalar field potential. This helps us derive a criterion for the symmetron model, but same argument can be applied to other scalar-tensor theories of generalized Brans-Dicke type. We consider two scenarios, one where the scalar field is only coupled to dark matter and where it couples to all of the matter.
description: 9 pages + Appendix, 4 figures, matches the version accepted to JCAP
Magnetic Zero-Modes, Vortices and Cartan Geometry
Creators: name: Ross, Calum
name: Schroers, Bernd
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We show that magnetic zero-modes of the Dirac operator on $\mathbb{R}^3$ which obey an additional non-linear equation are closely related to vortex configurations on the 2-sphere, and that both are best understood in terms of the geometry induced on the 3-sphere via pull-back of the round geometry with bundle maps of the Hopf fibration. We use this viewpoint to deduce a manifestly smooth formula for square-integrable magnetic zero-modes in terms of two homogeneous polynomials in two complex variables.
description: 33 pages, 3 figures. LMP accepted version
Anomalous Induced Density of Supercritical Coulomb Impurities in Graphene Under Strong Magnetic Fields
Creators: name: Le, Hoang-Anh
name: Yang, S. -R. Eric
Publisher: name: arXiv
Year: 2024
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: The Coulomb impurity problem of graphene, in the absence of a magnetic field, displays discrete scale invariance. Applying a magnetic field introduces a new magnetic length scale $\ell$ and breaks discrete scale invariance. Moreover, a magnetic field is a singular perturbation as it turns complex energies into real energies. Nonetheless, the Coulomb potential must be regularized with a length $R$ at short distances for supercritical impurities. We investigate the structure of the induced density of a filled Landau impurity band in the supercritical regime. The coupling between Landau level states by the impurity potential is nontrivial and can lead to several anomalous effects. First, we find that the peak in the induced density can be located away from the center of the impurity, depending on the characteristics of the Landau impurity bands. Second, the impurity charge is screened, despite the Landau impurity band being filled. Third, anticrossing impurity states lead to additional impurity cyclotron resonances.
Non-Adiabatic Approximations in Time-Dependent Density Functional Theory: Progress and Prospects
Creators: name: Lacombe, Lionel
name: Maitra, Neepa T.
Publisher: name: arXiv
Year: 2023
Subjects: subject: Chemical Physics (physics.chem-ph)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Time-dependent density functional theory continues to draw a large number of users in a wide range of fields exploring myriad applications involving electronic spectra and dynamics. Although in principle exact, the predictivity of the calculations is limited by the available approximations for the exchange-correlation functional. In particular, it is known that the exact exchange-correlation functional has memory-dependence, but in practise adiabatic approximations are used which ignore this. Here we review the development of non-adiabatic functional approximations, their impact on calculations, and challenges in developing practical and accurate memory-dependent functionals for general purposes.
Redrawing the Planners’ Circle
Creators: name: Merlin, Louis A.
name: Teoman, Denis
name: Viola, Marco
name: Vaughn, Hailey
name: Buehler, Ralph
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Biophysics
subject: Biochemistry
subject: Physical Sciences not elsewhere classified
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Inorganic Chemistry
subject: FOS: Chemical sciences

description: For decades, planners have been drawing circles of a quarter-mile radius to determine easily walkable distances for neighborhood and activity center planning. However, the radius of such “planners’ circles,” or walksheds, is often informed more by convention than by data. Here we examine walk-trip distances based on two national household travel surveys for the United States and Germany. We describe how walk distances vary by personal and trip characteristics, with a particular focus on trip purpose and pedestrian age. We conducted both univariate and multivariate analyses to compare patterns between the United States and Germany. The multivariate analysis examines quantile regressions for 50th, 75th, and 90th percentiles to understand both typical and longer walk distances. The observed distances that people walk vary significantly across age groups, trip purposes, and national contexts. Leisure trips tend to be longest, whereas shopping and errand trips tend to be shortest. There are substantial differences between the United States and Germany in the average lengths of walks (mean/median walk distance: Germany, 1,490/980 m, 0.93/0.61 miles; United States, 970/530 m, 0.60/0.33 miles) and in the effects of independent variables. A significant portion of the variation in walk-trip distances between the United States and Germany is likely due to Germany’s higher quality walk environments. Rather than always resort to a quarter-mile or 400-m radius, planners can use the data here to customize the size of the planners’ circle, or walkshed, they draw to take into account the primary trip purposes and demographic segments under consideration. Moreover, planners can draw circles with a shorter radius corresponding to the 50th percentile to plan for the most common walk-trip lengths while also considering larger circles corresponding to the 75th and 90th percentiles to provide more supportive and safer pedestrian environments for longer trips.
Identification of release sources in advection-diffusion system by machine learning combined with Green function inverse method
Creators: name: Stanev, Valentin G.
name: Iliev, Filip L.
name: Hansen, Scott
name: Vesselinov, Velimir V.
name: Alexandrov, Boian S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Machine Learning (cs.LG)
subject: Machine Learning (stat.ML)
subject: FOS: Computer and information sciences
subject: 68T10

description: The identification of sources of advection-diffusion transport is based usually on solving complex ill-posed inverse models against the available state- variable data records. However, if there are several sources with different locations and strengths, the data records represent mixtures rather than the separate influences of the original sources. Importantly, the number of these original release sources is typically unknown, which hinders reliability of the classical inverse-model analyses. To address this challenge, we present here a novel hybrid method for identification of the unknown number of release sources. Our hybrid method, called HNMF, couples unsupervised learning based on Nonnegative Matrix Factorization (NMF) and inverse-analysis Green functions method. HNMF synergistically performs decomposition of the recorded mixtures, finds the number of the unknown sources and uses the Green function of advection-diffusion equation to identify their characteristics. In the paper, we introduce the method and demonstrate that it is capable of identifying the advection velocity and dispersivity of the medium as well as the unknown number, locations, and properties of various sets of synthetic release sources with different space and time dependencies, based only on the recorded data. HNMF can be applied directly to any problem controlled by a partial-differential parabolic equation where mixtures of an unknown number of sources are measured at multiple locations.
Cross-modal Contrastive Learning for Multimodal Fake News Detection
Creators: name: Wang, Longzheng
name: Zhang, Chuang
name: Xu, Hongbo
name: Xu, Yongxiu
name: Xu, Xiaohan
name: Wang, Siqi
Publisher: name: arXiv
Year: 2023
Subjects: subject: Machine Learning (cs.LG)
subject: Artificial Intelligence (cs.AI)
subject: Computation and Language (cs.CL)
subject: FOS: Computer and information sciences

description: Automatic detection of multimodal fake news has gained a widespread attention recently. Many existing approaches seek to fuse unimodal features to produce multimodal news representations. However, the potential of powerful cross-modal contrastive learning methods for fake news detection has not been well exploited. Besides, how to aggregate features from different modalities to boost the performance of the decision-making process is still an open question. To address that, we propose COOLANT, a cross-modal contrastive learning framework for multimodal fake news detection, aiming to achieve more accurate image-text alignment. To further improve the alignment precision, we leverage an auxiliary task to soften the loss term of negative samples during the contrast process. A cross-modal fusion module is developed to learn the cross-modality correlations. An attention mechanism with an attention guidance module is implemented to help effectively and interpretably aggregate the aligned unimodal representations and the cross-modality correlations. Finally, we evaluate the COOLANT and conduct a comparative study on two widely used datasets, Twitter and Weibo. The experimental results demonstrate that our COOLANT outperforms previous approaches by a large margin and achieves new state-of-the-art results on the two datasets.
description: 9 pages, 3 figures
Riders Who Avoided Public Transit During COVID-19
Creators: name: Palm, Matthew
name: Allen, Jeff
name: Liu, Bochu
name: Zhang, Yixue
name: Widener, Michael
name: Farber, Steven
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Medicine
subject: Ecology
subject: FOS: Biological sciences
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Science Policy

description: Millions of North Americans stopped riding public transit in response to COVID-19. We treat this crisis as a natural experiment to illustrate the importance of public transit in riders’ abilities to access essential destinations. We measured the impacts of riders forgoing transit through a survey of transportation barriers completed by more than 4,000 transit riders in Toronto and Vancouver (Canada). We used Heckman selection models to predict six dimensions of transport disadvantage and transport-related social exclusions captured in our survey. We then complemented model results with an analysis of survey comments describing barriers that individuals faced. Lack of access to alternative modes is the strongest predictor of a former rider experiencing transport disadvantage, particularly neighborhood walkability and vehicle ownership. Groups at risk of transport disadvantage before COVID-19, particularly women and people in poorer health, were also more likely to report difficulties while avoiding public transit. Barriers described by respondents included former supports no longer offering rides, gendered household car use dynamics, and lack of culturally specific or specialized amenities within walking distance. Policymakers should plan for a level of redundancy in transportation systems that enables residents to access essential destinations when unexpected service losses occur. Designing communities that enable residents to walk to those essential destinations will help reduce the burdens faced by transit riders during crises that render transit unfeasible. At the same time, planners championing active travel as an alternative to transit during such crises also need to devise solutions for former transit riders for whom active travel is ill suited, for example, due to physical challenges with carrying groceries or needing to chaperone children.
On the Xiao conjecture for plane curves
Creators: name: Favale, Filippo Francesco
name: Naranjo, Juan Carlos
name: Pirola, Gian Pietro
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14H50, 14D06, 14J99, 14B10

description: Let $f: S\longrightarrow B$ be a non-trivial fibration from a complex projective smooth surface $S$ to a smooth curve $B$ of genus $b$. Let $c_f$ the Clifford index of the generic fibre $F$ of $f$. In [arXiv:1401.7502v4] it is proved that the relative irregularity of $f$, $q_f=h^{1,0}(S)-b$ is less than or equal to $g(F)-c_f$. In particular this proves the (modified) Xiao's conjecture: $q_f\le 1+g(F)/2$ for fibrations of general Clifford index. In this short note we assume that the generic fiber of $f$ is a plane curve of degree $d\ge 5$ and we prove that $q_f\le g(F)-c_f-1$. In particular we obtain the conjecture for families of quintic plane curves. This theorem is implied for the following result on infinitesimal deformations: let $F$ a smooth plane curve of degree $d\ge 5$ and let $ξ$ be an infinitesimal deformation of $F$ preserving the planarity of the curve. Then the rank of the cup-product map $\cdot ξ: H^0(F,ω_F) \rightarrow H^1(F,O_F)$ is at least $d-3$. We also show that this bound is sharp.
description: 8 pages. Some typos have been corrected. To appear in "Geometriae Dedicata"
Perfectly localized Majorana corner modes in fermionic lattices
Creators: name: Poduval, Prathyush P.
name: Schmidt, Thomas L.
name: Haller, Andreas
Publisher: name: arXiv
Year: 2023
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: Focusing on examples of Majorana zero modes on the corners of a two-dimensional lattice, we introduce a method to find parameter regions where the Majorana modes are perfectly localized on a single site. Such a limit allows us to study the dimerization structure of the sparse bulk Hamiltonian that results in the higher-order topology of the system. Furthermore, such limits typically provide an analytical understanding of the system energy scales. Based on the dimerization structure we extract from the two-dimensional model, we identify a more general stacking procedure to construct Majorana zero modes in arbitrary corners of a $d$-dimensional hypercube, which we demonstrate explicitly in $d\leq3$.
description: 12 pages, 12 figures
$1/N_c$ Nambu -- Jona-Lasinio model: $π^0$, $η$ and $η'$ mesons
Creators: name: Osipov, A. A.
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We continue to study the properties of the light pseudoscalar nonet within the combined framework of Nambu -- Jona-Lasinio model and $1/N_c$ expansion, assuming that current quark masses count of order $\mathcal O(1/N_c)$. The masses, mixing angles and decay constants of the $π^0$, $η$ and $η'$ are calculated. The role of the $U(1)_A$ anomaly is emphasized. It is shown that the gluon anomaly suppresses the leading order effects that might otherwise be substantial for the $η\to 3π$ amplitude. A detailed comparison with the known results of $1/N_c$ chiral perturbation theory is made.
description: 15 pages, 2 figures, final version to be published in PRD
Convex Relaxations of Chance Constrained AC Optimal Power Flow
Creators: name: Venzke, Andreas
name: Halilbasic, Lejla
name: Markovic, Uros
name: Hug, Gabriela
name: Chatzivasileiadis, Spyros
Publisher: name: arXiv
Year: 2017
Subjects: subject: Systems and Control (eess.SY)
subject: FOS: Electrical engineering, electronic engineering, information engineering

description: High penetration of renewable energy sources and the increasing share of stochastic loads require the explicit representation of uncertainty in tools such as the optimal power flow (OPF). Current approaches follow either a linearized approach or an iterative approximation of non-linearities. This paper proposes a semidefinite relaxation of a chance constrained AC-OPF which is able to provide guarantees for global optimality. Using a piecewise affine policy, we can ensure tractability, accurately model large power deviations, and determine suitable corrective control policies for active power, reactive power, and voltage. We state a tractable formulation for two types of uncertainty sets. Using a scenario-based approach and making no prior assumptions about the probability distribution of the forecast errors, we obtain a robust formulation for a rectangular uncertainty set. Alternatively, assuming a Gaussian distribution of the forecast errors, we propose an analytical reformulation of the chance constraints suitable for semidefinite programming. We demonstrate the performance of our approach on the IEEE 24 and 118 bus system using realistic day-ahead forecast data and obtain tight near-global optimality guarantees.
“Ambiguous, Confusing, and Not Delivering Enough Housing”
Creators: name: Raynor, Katrina
name: Palm, Matthew
name: Warren-Myers, Georgia
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Neuroscience
subject: Pharmacology
subject: Biotechnology
subject: Mental Health
subject: Infectious Diseases
subject: FOS: Health sciences

description: Responsibility for affordable housing delivery is increasingly being delivered through collaborations between private, nonprofit, and state actors and operationalized through voluntary negotiations. Negotiation theory provides a lens for understanding why outcomes are often limited by highlighting the impact of stakeholder interests, the potential for mutual gains, trust between negotiating partners, and access to information. We surveyed 148 housing stakeholders in the state of Victoria (Australia) shortly after the passage of legislation that supported the negotiation of voluntary affordable housing agreements. We found that stakeholders share a belief in the necessity of affordable housing. However, the current institutional context often precludes opportunities for mutual gain because there is little incentive to engage in negotiations, provision of sufficient incentives is problematic, and contributions are difficult to enforce. We found large discrepancies in levels of training in development feasibility across sectors and low trust between negotiation participants. We argue that these factors are likely to reduce the efficiency and effectiveness of voluntary affordable housing negotiations in Victoria and other jurisdictions with weak institutional arrangements for affordable housing negotiations. Across sectors, respondents prefer mandatory rather than voluntary affordable housing provisions. Voluntary affordable housing negotiations are unlikely to be effective without institutional scaffolding to ensure that negotiations result in mutual gains for stakeholders. Planners should pair the introduction of voluntary affordable housing negotiations with training resources for the stakeholders who will participate in negotiations as well as mechanisms for enforcing negotiated agreements.
Diophantine equations defined by binary quadratic forms over rational function fields
Creators: name: Lv, Chang
Publisher: name: arXiv
Year: 2017
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: Primary 11E12, 11D57, 11R58, Secondary 14L30, 11R37

description: We study the ``imaginary" binary quadratic form equations ax^2+bxy+cy^2+g=0 over k[t] in rational function fields, showing that a condition with respect to the Artin reciprocity map, is the only obstruction to the local-global principle for integral solutions of the equation.
description: 14 pages, git commit 20170117/57d58b6, to appear in Acta Arithmetica
Noether's Theorem in Multisymplectic Geometry
Creators: name: Herman, Jonathan
Publisher: name: arXiv
Year: 2017
Subjects: subject: Symplectic Geometry (math.SG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences

description: We extend Noether's theorem to the setting of multisymplectic geometry by exhibiting a correspondence between conserved quantities and continuous symmetries on a multi-Hamiltonian system. We show that a homotopy co-momentum map interacts with this correspondence in a way analogous to the moment map in symplectic geometry. We apply our results to generalize the theory of the classical momentum and position functions from the phase space of a given physical system to the multisymplectic phase space. We also apply our results to manifolds with a torsion-free $G_2$ structure.
description: 36 pages. For version 2: Incorporated the referee's suggestions and fixed some typos. To appear in Differential Geometry and its Applications
Bell's nonlocality in a general nonsignaling case: quantitatively and conceptually
Creators: name: Loubenets, Elena R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Physics (quant-ph)
subject: Mathematical Physics (math-ph)
subject: Probability (math.PR)
subject: History and Philosophy of Physics (physics.hist-ph)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: Quantum violation of Bell inequalities is now used in many quantum information applications and it is important to analyze it both quantitatively and conceptually. In the present paper, we analyze violation of multipartite Bell inequalities via the local probability model - the LqHV (local quasi hidden variable) model [Loubenets, J. Math. Phys. 53, 022201 (2012)], incorporating the LHV model only as a particular case and correctly reproducing the probabilistic description of every quantum correlation scenario, more generally, every nonsignaling scenario. The LqHV probability framework allows us to construct nonsignaling analogs of Bell inequalities and to specify parameters quantifying violation of Bell inequalities - Bell's nonlocality - in a general nonsignaling case. For quantum correlation scenarios on an N-qudit state, we evaluate these nonlocality parameters analytically in terms of dilation characteristics of an N-qudit state and also, numerically - in d and N. In view of our rigorous mathematical description of Bell's nonlocality in a general nonsignaling case via the local probability model, we argue that violation of Bell inequalities in a quantum case is not due to violation of the Einstein-Podolsky-Rosen (EPR) locality conjectured by Bell but due to the improper HV modelling of "quantum realism".
description: 10 pages, reported at the International Conference "Quantum and Beyond", June 2016, Sweden
Rapidity dependence of transverse-momentum multiplicity correlations
Creators: name: Bzdak, Adam
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: High Energy Physics - Experiment (hep-ex)
subject: Nuclear Experiment (nucl-ex)
subject: Nuclear Theory (nucl-th)
subject: FOS: Physical sciences

description: Following previous work [1], we propose to analyze the rapidity dependence of transverse momentum and transverse-momentum multiplicity correlations. We demonstrate that the orthogonal polynomial expansion of the latter has the potential to discriminate between models of particle production.
description: 3 pages; published version
The Ubiquity of Smooth Hilbert Schemes
Creators: name: Staal, Andrew P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Algebraic Geometry (math.AG)
subject: FOS: Mathematics
subject: 14C05 (Primary) 14Q15, 13A02 (Secondary)

description: We investigate the geography of Hilbert schemes parametrizing closed subschemes of projective space with specified Hilbert polynomials. We classify Hilbert schemes with unique Borel-fixed points via combinatorial expressions for their Hilbert polynomials. These expressions naturally lead to an arrangement of nonempty Hilbert schemes as the vertices of an infinite full binary tree. Here we discover regularities in the geometry of Hilbert schemes. Specifically, under natural probability distributions on the tree, we prove that Hilbert schemes are irreducible and nonsingular with probability greater than $0.5$.
description: 19 pages, 2 figures, accepted version, to appear in Math. Z
Evolution of a beam dynamics model for the transport lines in a proton therapy facility
Creators: name: Rizzoglio, V.
name: Adelmann, A.
name: Baumgarten, C.
name: Frey, M.
name: Gerbershagen, A.
name: Meer, D.
name: Schippers, J. M.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Accelerator Physics (physics.acc-ph)
subject: FOS: Physical sciences

description: Despite the fact that the first-order beam dynamics models allow an approximated evaluation of the beam properties, their contribution is essential during the conceptual design of an accelerator or beamline. However, during the commissioning some of their limitations appear in the comparison against measurements. The extension of the linear model to higher order effects is, therefore, demanded. In this paper, the effects of particle-matter interaction have been included in the model of the transport lines in the proton therapy facility at the Paul Scherrer Institut (PSI) in Switzerland. To improve the performance of the facility, a more precise model was required and has been developed with the multi-particle open source beam dynamics code called OPAL (Object oriented Particle Accelerator Library). In OPAL, the Monte Carlo simulations of Coulomb scattering and energy loss are performed seamless with the particle tracking. Beside the linear optics, the influence of the passive elements (e.g. degrader, collimators, scattering foils and air gaps) on the beam emittance and energy spread can be analysed in the new model. This allows for a significantly improved precision in the prediction of beam transmission and beam properties. The accuracy of the OPAL model has been confirmed by numerous measurements.
description: 17 pages, 19 figures
Gaussian Multiple Access Channels with One-Bit Quantizer at the Receiver
Creators: name: Rassouli, Borzoo
name: Varasteh, Morteza
name: Gunduz, Deniz
Publisher: name: arXiv
Year: 2017
Subjects: subject: Information Theory (cs.IT)
subject: FOS: Computer and information sciences

description: The capacity region of a two-transmitter Gaussian multiple access channel (MAC) under average input power constraints is studied, when the receiver employs a zero-threshold one-bit analog-to-digital converter (ADC). It is proved that the input distributions of the two transmitters that achieve the boundary points of the capacity region are discrete. Based on the position of a boundary point, upper bounds on the number of the mass points of the corresponding distributions are derived.
description: 25 pages, 3 figures, revised version submitted to IEEE Transactions on Information Theory
Consistency Analysis for Massively Inconsistent Datasets in Bound-to-Bound Data Collaboration
Creators: name: Hegde, Arun
name: Li, Wenyu
name: Oreluk, James
name: Packard, Andrew
name: Frenklach, Michael
Publisher: name: arXiv
Year: 2017
Subjects: subject: Optimization and Control (math.OC)
subject: Computational Engineering, Finance, and Science (cs.CE)
subject: FOS: Mathematics
subject: FOS: Computer and information sciences

description: Bound-to-Bound Data Collaboration (B2BDC) provides a natural framework for addressing both forward and inverse uncertainty quantification problems. In this approach, QOI (quantity of interest) models are constrained by related experimental observations with interval uncertainty. A collection of such models and observations is termed a dataset and carves out a feasible region in the parameter space. If a dataset has a nonempty feasible set, it is said to be consistent. In real-world applications, it is often the case that collections of experiments and observations are inconsistent. Revealing the source of this inconsistency, i.e., identifying which models and/or observations are problematic, is essential before a dataset can be used for prediction. To address this issue, we introduce a constraint relaxation-based approach, entitled the vector consistency measure, for investigating datasets with numerous sources of inconsistency. The benefits of this vector consistency measure over a previous method of consistency analysis are demonstrated in two realistic gas combustion examples.
description: 31 pages, published in SIAM/ASA Journal on Uncertainty Quantification
Symmetric and Asymmetric Reheating
Creators: name: Hardy, Edward
name: Unwin, James
Publisher: name: arXiv
Year: 2017
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We study models in which the inflaton is coupled to two otherwise decoupled sectors, and the effect of preheating and related processes on their energy densities during the evolution of the universe. Over most of parameter space, preheating is not disrupted by the presence of extra sectors, and even comparatively weakly coupled sectors can get an order 1 fraction of the total energy at this time. If two sectors are both preheated, the high number densities could also lead to inflaton mediated thermalisation. If only one sector is preheated, Bose enhancement of the late time inflaton decays may cause significant deviations from the perturbative prediction for their relative reheat temperatures. Meanwhile, in Non-Oscillatory inflation models resonant effects can result in exponentially large final temperature differences between sectors that have similar couplings to the inflaton. Asymmetric reheating is potentially relevant for a range of beyond the Standard Model physics scenarios. We show that in dark matter freeze-in models, hidden sector temperatures a factor of 10 below that of the visible sector are typically needed for the relic abundance to be set solely by freeze-in dynamics.
description: JHEP version
Transferring Vacant Lots to Private Ownership Improves Care and Empowers Residents
Creators: name: Rigolon, Alessandro
name: Banerjee, Debolina
name: Gobster, Paul
name: Hadavi, Sara
name: Stewart, William
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Space Science
subject: Medicine
subject: Cell Biology
subject: Sociology
subject: FOS: Sociology
subject: Biological Sciences not elsewhere classified
subject: Cancer
subject: Science Policy
subject: Infectious Diseases
subject: FOS: Health sciences
subject: Virology

description: Several U.S. cities have implemented vacant lot greening programs as planning strategies to address decreased tax base, crime, and other issues associated with high land vacancy in marginalized neighborhoods, yet little is known about the benefits of programs that transfer city-owned lots to private owners. Using a mixed methods approach, we studied whether and how private ownership matters for vacant lot condition-care in Chicago’s (IL) Large Lot Program, which allows property owners to purchase vacant city lots on their block for $1. We compared visual changes in vacant lot condition-care between the purchased “treatment” lots and matched “control” lots through a difference-in-differences technique. Our findings demonstrate a causal effect of private ownership: Whereas condition-care of the control lots decreased between 2014 and 2018, it significantly increased for treatment lots in the year after sale (2015) and continued to rise through 2018. Also, increases in Large Lot condition-care did not vary based on whether owners lived on the block. Focus groups with Large Lot owners showed that ownership empowers residents by reducing illicit and dangerous behaviors, expressing an ethic of care through vacant lot improvement, and continuing a legacy of land tenure tied to family and neighborhood. Further research is needed to strengthen our understanding of spatial contagion effects from treatment to nearby control lots. Our findings show that ownership-based vacant land greening initiatives like the Large Lot Program effectively improve condition-care regardless of whether lot owners live on the same block. Focus group findings suggest that such initiatives could be integrated into community-based safety programs and could be boosted by funding to create community amenities.
Tools of the Trade?
Creators: name: Siddiq, Fariba
name: Taylor, Brian D.
Publisher: name: Taylor & Francis
Year: 2021
Subjects: subject: Cell Biology
subject: Genetics
subject: FOS: Biological sciences
subject: Physiology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Ecology
subject: Information Systems not elsewhere classified
subject: Developmental Biology
subject: Cancer
subject: Inorganic Chemistry
subject: FOS: Chemical sciences
subject: Science Policy
subject: Plant Biology

description: A growing number of planning researchers and practitioners argue for a shift from mobility-centered transportation planning to an accessibility-focused one. Accessibility is a compelling concept that has proven more difficult to operationalize than mobility, which helps to explain why so many accessibility metrics have been developed for urban research and planning practice. To assess the state of these metrics, we reviewed 54 of them in light of their theoretical basis, data requirements, units of analysis, travel modes and trip purposes accounted for, and potential applications to planning practice. We also reviewed the substantial literature on accessibility measurement and interviewed planning practitioners who are applying accessibility metrics in practice. We find that accessibility theory and measurement has advanced more rapidly than applications in practice. However, a new generation of tools is emerging that may accelerate the move to accessibility planning. Although many of the measures focus on a single travel mode, the number of multimodal metrics is growing. Most of the measures are designed for regional-scale planning and scenario evaluation; only a few to date are intended for project evaluation. The 54 accessibility metrics and tools we reviewed vary widely and none stands out as obviously superior for planning practice. Although most calculate the accessibility of places, and many do so reasonably well, we see the most promise in measures of the accessibility of travelers, which can then be aggregated for place-based analyses while still shedding light on how access can vary substantially across different types of travelers. The principal challenge to broadly deploying accessibility analyses in practice in the years ahead is in developing measures that meaningfully measure the many salient dimensions of access, have manageable data requirements, and are understandable to planners, public officials, and community members.
The variety of $2$-dimensional algebras over an algebraically closed field
Creators: name: Kaygorodov, Ivan
name: Volkov, Yury
Publisher: name: arXiv
Year: 2017
Subjects: subject: Rings and Algebras (math.RA)
subject: FOS: Mathematics

description: The work is devoted to the variety of $2$-dimensional algebras over an algebraically closed field. Firstly, we classify such algebras modulo isomorphism. Then we describe the degenerations and the closures of principal algebra series in the variety under consideration. Finally, we apply our results to obtain analogous descriptions for the subvarieties of flexible, and bicommutative algebras. In particular, we describe rigid algebras and irreducible components for these subvarieties.
‘Life should go on’: a qualitative inquiry of parental reactions, experiences, and perceived needs following adolescents’ recent traumatic exposure
Creators: name: Kerbage, Hala
name: Elbejjani, Martine
name: El-Hage, Wissam
name: Purper-Ouakil, Diane
Publisher: name: Taylor & Francis
Year: 2024
Subjects: Biophysics
Medicine
Neuroscience
Environmental Sciences not elsewhere classified
Biological Sciences not elsewhere classified
Science Policy
Mental Health

description: Background: Parents have a significant role in supporting children who have been exposed to traumatic events. Little is known about parental experiences and needs in the wake of traumatic exposure, which could help in designing tailored early interventions. Objective: This qualitative study explored experiences, perceived needs, and factors impacting those needs being met, in parents of adolescents aged 11–16 years who had been exposed in the past 3 months to a potentially traumatic event, in the city of Montpellier, France. Method: We purposively sampled 34 parents of 25 adolescents aged 11–16 years meeting the inclusion criteria and used semi-structured in-depth interviews. Thematic analysis was applied using a multistage recursive coding process. Results: Parents lacked trauma-informed explanations to make sense of their child’s reduced functioning. They experienced stigma attached to the victim label and were reluctant to seek help. School avoidance and lack of collaboration with schools were major obstacles experienced by parents. Parents trying to navigate conflicting needs fell into two distinct categories. Those who experienced distressing levels of shame and guilt tended to avoid discussing the traumatic event with their child, pressuring them to resume life as it was before, despite this perpetuating conflictual interactions. Others adapted by revisiting their beliefs that life should go on as it was before and by trying to come up with new functional routines, which improved their relationship with their child and helped them to restore a sense of agency and hope, but at the cost of questioning their parental role. Conclusions: Key domains of parental experiences could provide potential early intervention targets, such as psychoeducation on traumatic stress, representations about recovery and the victim status, parent–child communication, and involvement of schools and primary caregivers. Further research is needed to validate the impact of these domains in early post-traumatic interventions. Parents of teenagers exposed to traumatic events struggle to understand trauma and feel isolated.Parents feel pressured to resume life as it was before, leading to conflictual child–parent interaction.Psychoeducation, stigma, and school involvement could be early intervention targets. Parents of teenagers exposed to traumatic events struggle to understand trauma and feel isolated. Parents feel pressured to resume life as it was before, leading to conflictual child–parent interaction. Psychoeducation, stigma, and school involvement could be early intervention targets.
Macroscopic superpositions require tremendous measurement devices
Creators: name: Skotiniotis, M.
name: Dür, W.
name: Sekatski, P.
Publisher: name: arXiv
Year: 2017
Subjects: subject: Quantum Physics (quant-ph)
subject: FOS: Physical sciences

description: We consider fundamental limits on the detectable size of macroscopic quantum superpositions. We argue that a full quantum mechanical treatment of system plus measurement device is required, and that a (classical) reference frame for phase or direction needs to be established to certify the quantum state. When taking the size of such a classical reference frame into account, we show that to reliably distinguish a quantum superposition state from an incoherent mixture requires a measurement device that is quadratically bigger than the superposition state. Whereas for moderate system sizes such as generated in previous experiments this is not a stringent restriction, for macroscopic superpositions of the size of a cat the required effort quickly becomes intractable, requiring measurement devices of the size of the Earth. We illustrate our results using macroscopic superposition states of photons, spins, and position. Finally, we also show how this limitation can be circumvented by dealing with superpositions in relative degrees of freedom.
description: 20 pages (including appendices), 1 Figure
Blow-up analysis concerning singular Trudinger-Moser inequalities in dimension two
Creators: name: Yang, Yunyan
name: Zhu, Xiaobao
Publisher: name: arXiv
Year: 2016
Subjects: subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 46E35

description: In this paper, we derive a sharp version of the singular Trudinger-Moser inequality, which was originally established by Adimurthi and Sandeep (Nonlinear Differ. Equ. Appl. 2007). Moreover, extremal functions for those singular Trudinger-Moser inequalities are also obtained. Our method is the blow-up analysis. Compared with our previous work (J. Differential Equations 2015), the essential difficulty caused by the presence of singularity is how to analyse the asymptotic behaviour of certain maximizing sequence near the blow-up point. We overcome this difficulty by combining two different classification theorems of Chen and Li (Duke Math. J. 1991; Duke Math. J. 1995) to get the desired bubble.
description: 22 pages
Cosmological signatures of ultralight dark matter with an axionlike potential
Creators: name: Cedeño, Francisco X. Linares
name: González-Morales, Alma X.
name: Ureña-López, L. Arturo
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Relativity and Quantum Cosmology (gr-qc)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: FOS: Physical sciences

description: Nonlinearities in a realistic axion field potential may play an important role in the cosmological dynamics. In this paper we use the Boltzmann code CLASS to solve the background and linear perturbations evolution of an axion field and contrast our results with those of CDM and the free axion case. We conclude that there is a slight delay in the onset of the axion field oscillations when nonlinearities in the axion potential are taken into account. Besides, we identify a tachyonic instability of linear modes resulting in the presence of a bump in the power spectrum at small scales. Some comments are in turn about the true source of the tachyonic instability, how the parameters of the axionlike potential can be constrained by Ly-$α$ observations, and the consequences in the stability of self-gravitating objects made of axions.
description: 7 pages, 4 figures. Matches version published in PRD
On correlations between class numbers of imaginary quadratic fields
Creators: name: Kumaraswamy, V. Vinay
Publisher: name: arXiv
Year: 2017
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 11E25, 11R29, 11P55

description: Let $h(-n)$ be the class number of the imaginary quadratic field with discriminant $-n$. We establish an asymtotic formula for correlations involving $h(-n)$ and $h(-n-l)$, over fundamental discriminants that avoid the congruence class $1\pmod{8}$. Our result is uniform in the shift $l$, and the proof uses an identity of Gauss relating $h(-n)$ to representations of integers as sums of three squares. We also prove analogous results on correlations involving $r_Q(n)$, the number of representations of an integer $n$ by an integral positive definite quadratic form $Q$.
description: Revised version
Economic Growth Model with Constant Pace and Dynamic Memory
Creators: name: Tarasova, Valentina V.
name: Tarasov, Vasily E.
Publisher: name: arXiv
Year: 2017
Subjects: subject: General Economics (econ.GN)
subject: FOS: Economics and business
subject: 91B02, 34A08, 26A33,

description: The article discusses a generalization of model of economic growth with constant pace, which takes into account the effects of dynamic memory. Memory means that endogenous or exogenous variable at a given time depends not only on their value at that time, but also on their values at previous times. To describe the dynamic memory we use derivatives of non-integer orders. We obtain the solutions of fractional differential equations with derivatives of non-integral order, which describe the dynamics of the output caused by the changes of the net investments and effects of power-law fading memory.
description: 7 pages, PDF
Improved bounds on the bosonic dark matter with pulsars in the Milky Way
Creators: name: Liang, Dicong
name: Shao, Lijing
Publisher: name: arXiv
Year: 2023
Subjects: subject: High Energy Astrophysical Phenomena (astro-ph.HE)
subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: Neutron stars (NSs) can be used to constrain dark matter (DM) since a NS can transform into a black hole (BH) if it captures sufficient DM particles and exceeds the Chandrasekhar limit. We extend earlier work and for the first time take into account the Galactic motion of individual NSs, which changes the amount of the captured DM by as large as one to two orders of magnitude. We systematically apply the analysis to 413 NSs in the Milky Way, and constrain the DM particle mass and its interaction with nucleon simultaneously. We find that the most stringent bound is placed by a few NSs and the bound becomes stronger after considering the Galactic motion. The survival of observed NSs already excludes a cross section $σ_{nX}\gtrsim 10^{-45} \, {\rm cm}^2$ for DM particles with mass from $100\, {\rm MeV}$ to $10^3 \, {\rm GeV}$. Especially for a mass around $10 \, {\rm GeV}$, the constraint on the cross section is as stringent as $σ_{nX}\lesssim 10^{-49} \, {\rm cm}^2$.
description: 18 pages, 4 figures
Times Square Sampling: An Adaptive Algorithm for Free Energy Estimation
Creators: name: Predescu, Cristian
name: Snarski, Michael
name: Robinson-Mosher, Avi
name: Sritharan, Duluxan
name: Szalay, Tamas
name: Shaw, David E.
Publisher: name: Taylor & Francis
Year: 2024
Subjects: subject: Genetics
subject: FOS: Biological sciences
subject: Molecular Biology
subject: Biotechnology
subject: Environmental Sciences not elsewhere classified
subject: Biological Sciences not elsewhere classified
subject: Information Systems not elsewhere classified
subject: Mathematical Sciences not elsewhere classified
subject: Science Policy
subject: Computational Biology

description: Estimating free energy differences, an important problem in computational drug discovery and in a wide range of other application areas, commonly involves a computationally intensive process of sampling a family of high-dimensional probability distributions and a procedure for computing estimates based on those samples. The variance of the free energy estimate of interest typically depends strongly on how the total computational resources available for sampling are divided among the distributions, but determining an efficient allocation is difficult without sampling the distributions. Here we introduce the Times Square sampling algorithm, a novel on-the-fly estimation method that dynamically allocates resources in such a way as to significantly accelerate the estimation of free energies and other observables, while providing rigorous convergence guarantees for the estimators. We also show that it is possible, surprisingly, for on-the-fly free energy estimation to achieve lower asymptotic variance than the maximum-likelihood estimator MBAR, raising the prospect that on-the-fly estimation could reduce variance in a variety of other statistical applications. Supplementary materials for this article are available online.