cometadata/datacite-rtg-text-other-reclassification-records huggingface dataset:
Recent progress and review of issues related to Physics Dynamics Coupling in geophysical models
Creators: name: Gross, Markus
name: Wan, Hui
name: Rasch, Philip J.
name: Caldwell, Peter M.
name: Williamson, David L.
name: Klocke, Daniel
name: Jablonowski, Christiane
name: Thatcher, Diana R.
name: Wood, Nigel
name: Cullen, Mike
name: Beare, Bob
name: Willett, Martin
name: Lemarié, Florian
name: Blayo, Eric
name: Malardel, Sylvie
name: Termonia, Piet
name: Gassmann, Almut
name: Lauritzen, Peter H.
name: Johansen, Hans
name: Zarzycki, Colin M.
name: Sakaguchi, Koichi
name: Leung, Ruby
Publisher: name: arXiv
Year: 2016
Subjects: subject: Atmospheric and Oceanic Physics (physics.ao-ph)
subject: FOS: Physical sciences

description: Geophysical models of the atmosphere and ocean invariably involve parameterizations. These represent two distinct areas: Subgrid processes that the model cannot resolve, and diabatic sources in the equations, due to radiation for example. Hence, coupling between these physics parameterizations and the resolved fluid dynamics and also between the dynamics of the air and water, is necessary. In this paper weather and climate models are used to illustrate the problems. Nevertheless the same applies to other geophysical models. This coupling is an important aspect of geophysical models. However, often model development is strictly segregated into either physics or dynamics. As a consequence, this area has many unanswered questions. Recent developments in the design of dynamical cores, extended process physics and predicted future changes of the computational infrastructure are increasing complexity. This paper reviews the state-of-the-art of the physics-dynamics coupling in geophysical models, surveys the analysis techniques, and illustrates open questions in this field. This paper focuses on two objectives: To illustrate the phenomenology of the coupling problem with references to examples in the literature and to show how the problem can be analysed. Proposals are made on how to advance the understanding and upcoming challenges with emerging modeling strategies. This paper is of interest to model developers who aim to improve the models and have to make choices on and test new implementations, to users who have to understand choices presented to them and finally users of outputs, who have to distinguish physical features from numerical problems in the model data.
UV contribution and power dependence on $Λ_\mathrm{QCD}$ of Adler function
Creators: name: Mishima, Go
name: Sumino, Yukinari
name: Takaura, Hiromasa
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: FOS: Physical sciences

description: We formulate a way to separate UV and IR contributions to the Adler function and discuss how $Λ_\mathrm{QCD}^2/Q^2$ dependence is encoded in the UV contribution within perturbative QCD.
description: 10 pages, 5 figures. v3: minor modifications
DAHA and plane curve singularities
Creators: name: Cherednik, Ivan
name: Philipp, Ian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantum Algebra (math.QA)
subject: Algebraic Geometry (math.AG)
subject: Representation Theory (math.RT)
subject: FOS: Mathematics

description: We suggest a relatively simple and totally geometric conjectural description of uncolored DAHA superpolynomials of arbitrary algebraic knots (conjecturally coinciding with the reduced stable Khovanov-Rozansky polynomials) via the flagged Jacobian factors (new objects) of the corresponding unibranch plane curve singularities. This generalizes the Cherednik-Danilenko conjecture on the Betti numbers of Jacobian factors, the Gorsky combinatorial conjectural interpretation of superpolynomials of torus knots and that by Gorsky-Mazin for their constant term. The paper mainly focuses on non-torus algebraic knots. A connection with the conjecture due to Oblomkov-Rasmussen-Shende is possible, but our approach is different. A motivic version of our conjecture is related to p-adic orbital A-type integrals for anisotropic centralizers.
description: v2: extensive editing, added refs, an extension toward orbital integrals; v3: some editing, confirmations for non-affine cells; v4: essentially equivalent to the AGT version
Spatial correlations, additivity and fluctuations in conserved-mass transport processes
Creators: name: Das, Arghya
name: Chatterjee, Sayani
name: Pradhan, Punyabrata
Publisher: name: arXiv
Year: 2016
Subjects: subject: Statistical Mechanics (cond-mat.stat-mech)
subject: FOS: Physical sciences

description: We exactly calculate two-point spatial correlation functions in steady state in a broad class of conserved-mass transport processes, which are governed by chipping, diffusion and coalescence of masses. We find that the spatial correlations are in general short-ranged and consequently, on a large scale, these conserved-mass transport processes possess a remarkable thermodynamic structure in the steady state. That is, the processes have an equilibriumlike additivity property, and a corresponding fluctuation-response relation, which helps us to obtain subsystem mass distributions in the limit of subsystem size large.
description: 13 pages, 8 figures (part of Sec. III modified, figs 6 and 7 replaced)
Positivity in power series rings
Creators: name: Cimpri, Jaka
name: Kuhlmann, Salma
name: Marshall, Murray
Publisher: name: Kooperation de Gruyter
Year: 2010

description: We extend and generalize results of Scheiderer (2006) on the representation of polynomials nonnegative on two-dimensional basic closed semialgebraic sets. Our extension covers some situations where the defining polynomials do not satisfy the transversality condition. Such situations arise naturally when one considers semialgebraic sets invariant under finite group actions.
Monocyte Macrophage Biomarkers of Multiple Sclerosis in an Underrepresented Minority Population
Creators: name: Bingen, Jeremy Michael
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Multiple Sclerosis (MS) is an autoimmune, inflammatory disease of the central nervous system and is one of the most common causes of neurological disability in young adults. Historically, this disease was predominantly studied in White individuals of European ancestry because of high disease prevalence in these populations. However, more recent work suggested Black American woman have the highest incidence of MS in the United States. In addition, Black and Hispanic Americans are at increased risk of developing more severe neurological disability. The work for this thesis focused on identification of differential DNA methylation and transcriptomics of peripheral myeloid cells because these biomarkers may best reflect the impact of environment determinants. Donor samples were from the UI Health Neuroimmunology Biobank, and approximately 55% of donors identify as Black or African American and 25% as Hispanic or Latino. Analysis of differential expression of mRNA splice variants in human macrophages revealed that splice variants of ATP5MPL, HSP90B1, PPP1R10, and SCN10A were associated with MS. These genes regulate cellular stress responses, and ATP5MPL and SCN10A were further characterized in their regulatory roles of mitochondrial respiration. Whole blood methylomic analysis of differential DNA methylation identified novel biomarkers of MS and revealed associations with pathways that regulate cellular proliferation and differentiation and host responses to GI pathogens. Single cell RNAseq analysis of human macrophages showed expansion of a potentially proinflammatory cellular subset in MS. Taken together, these results suggest novel mechanisms of MS pathogenesis that may increase the risk of severe forms of MS. The working model is that environmental regulators of cellular stress in myeloid cells mediate epigenetic modifications that lead to chronic inflammatory activation of macrophages and increased risk of disease susceptibility and severe clinical phenotypes of MS.
Increased metallicity of Carbon nanotubes because of incorporation of extended Stone-Wales' defects: an ab-initio real space approach
Creators: name: Datta, Sujoy
name: Sadhukhan, Banasree
name: Chaudhuri, Chhanda Basu
name: Chakraborty, Srabani
name: Mookerjee, Abhijit
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: FOS: Physical sciences

description: We propose an ab-initio combination of the Linear Muffin-Tin Orbital and the Recursion Methods to study the effect of extended Stone-Wales defects in single layer Carbon nanotubes. We have successfully applied this to zigzag and armchair tubes. The methodology involves no intrinsic mean-field like assumptions or external parameter fitting. As defects proliferate, the low density of states near the Fermi levels of the pristine tubes is filled with defect states. The increase of DOS at the Fermi level leads to enhanced conduction, which indicates enhanced metallicity due to SW defects in the nanotubes.
Exactly solvable cases in QED with t-electric potential steps
Creators: name: Adorno, T. C.
name: Gavrilov, S. P.
name: Gitman, D. M.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: FOS: Physical sciences

description: In this paper, we present in detail consistent QED (and scalar QED) calculations of particle creation effects in external electromagnetic field that correspond to three most important exactly solvable cases of t-electric potential steps: Sauter-like electric field, T-constant electric field, and exponentially growing and decaying electric fields. In all these cases, we succeeded to obtain new results, such as calculations in modified configurations of the above mentioned steps and detailed considerations of new limiting cases in already studied before steps. As was recently discovered by us, the information derived from considerations of exactly solvable cases allows one to make some general conclusions about quantum effects in fields for which no closed form solutions of the Dirac (or Klein-Gordon) equation are known. In the present article we briefly represent such conclusions about an universal behavior of vacuum mean values in slowly varying strong electric fields.
description: 61 pages, version accepted for publication in IJMPA, misprints corrected
Open source practices underpinning the SAFE-D principles
Creators: name: Whitaker, Kirstie Jane
Publisher: name: Zenodo
Year: 2023
Subjects: open source
open science
open source AI
responsible research and innovation
ethical data science

description: Kirstie's presentation as part of the OSI Deep Dive Webinar series on Defining Open Source AI in September 2023. Useful links: Webinar series: https://opensource.org/events/deep-dive-ai-webinar-series-2023 Overview of the session: https://deepdiveai.sessionize.com/session/529119
description: This work was supported by The UKRI Strategic Priorities Fund under the EPSRC Grant EP/T001569/1, particularly the "Tools, Practices and Systems" theme within that grant, and by The Alan Turing Institute under the EPSRC grant EP/N510129/1.
A nested polyhedra model of turbulence
Creators: name: Gürcan, Ö. D.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Fluid Dynamics (physics.flu-dyn)
subject: Numerical Analysis (math.NA)
subject: Cellular Automata and Lattice Gases (nlin.CG)
subject: FOS: Physical sciences
subject: FOS: Mathematics

description: A discretization of the wave-number space is proposed, using nested polyhedra, in the form of alternating dodecahedra and icosahedra that are self-similarly scaled. This particular choice allows the possibility of forming triangles using only discretized wave-vectors when the scaling between two consecutive dodecahedra is equal to the golden ratio, and the icosahedron between the two dodecahedra is the dual of the inner dodecahedron. Alternatively, the same discretization can be described as a logarithmically spaced (with a scaling equal to the golden ratio), nested dodecahedron-icosahedron compounds. A wave-vector which points from the origin to a vertex of such a mesh, can always find two other discretized wave-vectors that are also on the vertices of the mesh (which is not true for an arbitrary mesh). Thus, the nested polyhedra grid can be thought of as a reduction (or decimation) of the Fourier space using a particular set of self-similar triads aranged approximately in a spherical form. For each vertex (i.e. discretized wave-vector) in this space, there are either 9 or 15 pairs of vertices (i.e. wave-vectors) with which the initial vertex can interact to form a triangle. This allows the reduction of the convolution integral in the Navier-Stokes equation to a sum over 9 or 15 interaction pairs. Transforming the equation in Fourier space, to a network of interacting nodes, that can be constructed as a numerical model, which evolves each component of the velocity vector on each node of the network. Such a model gives the usual Kolmogorov spectrum. Since the scaling is logarithmic, and the number of nodes for each scale is constant, a very large inertial range can be considered with a much lower number of degrees of freedom. Incidentally, by assuming isotropy and a certain relation between the phases, the model can be used to systematically derive three dimensional shell models.
Strains differences in the collective behaviour of zebrafish (Danio rerio) in heterogeneous environment
Creators: name: Séguret, Axel
name: Collignon, Bertrand
name: Halloy, José
Publisher: name: arXiv
Year: 2016
Subjects: subject: Quantitative Methods (q-bio.QM)
subject: Populations and Evolution (q-bio.PE)
subject: FOS: Biological sciences

description: Recent studies show differences in individual motion and shoaling tendency between strains of the same species. Here, we analyse the collective motion and the response to visual stimuli in two morphologically different strains (TL and AB) of zebrafish. For both strains, we observe 10 groups of 5 and 10 zebrafish swimming freely in a large experimental tank with two identical attractive landmarks (cylinders or disks) for one hour. We track the positions of the fish by an automated tracking method and compute several metrics at the group level. First, the probability of presence shows that both strains avoid free space and are more likely to swim in the vicinity of the walls of the tank and the attractive landmarks. Second, the analysis of landmarks occupancy shows that AB zebrafish are more present in their vicinity than TL zebrafish and that both strains regularly transit from one landmark to the other with no preference on the long duration. Finally, TL zebrafish show a higher cohesion than AB zebrafish. Thus, landmarks and duration of the repicates allow to reveal collective behavioural variabilities among different strains of zebrafish. These results provide a new insight into the need to take into account individual variability of zebrafish strains for studying collective behaviour.
description: 14 pages, 21 figures, research study in quantitative collective behaviour
The analytic class number formula for $1$-dimensional affine schemes
Creators: name: Jordan, Bruce W.
name: Poonen, Bjorn
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics

description: We derive an analytic class number formula valid for an order in a product of $S$-integers in global fields, or equivalently for reduced finite-type affine schemes of pure dimension $1$ over $\mathbb{Z}$.
description: 15 pages; a second example, of a non-maximal order in a number field, was added. Some proofs are explained in more detail
Strain Effects in Topological Insulators: Topological Order and the Emergence of Switchable Topological Interface States in Sb$_2$Te$_3$/Bi$_2$Te$_3$ Heterojunctions
Creators: name: Aramberri, Hugo
name: Muñoz, M. Carmen
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mesoscale and Nanoscale Physics (cond-mat.mes-hall)
subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Strain can induce a topological phase transition in bismuth dichalcogenides. We present the phase diagram for 3D topological insulators Bi$_2$Te$_3$, Sb$_2$Te$_3$, Bi$_2$Se$_3$ and Sb$_2$Se$_3$ with uniaxial and biaxal strain, which show metallic and insulating phases, both topologically trivial and non-trivial. In particular, uniaxial tension can drive Sb$_2$Te$_3$ into a topologically trivial insulating phase. Thus, we propose a Sb$_2$Te$_3$/Bi$_2$Te$_3$ heterojunction in which a topological interface state arises in the common gap of this topological insulator-normal insulator heterojunction that can be switched on or off by means of uniaxial strain. This interface state is confined in the Sb$_2$Te$_3$ subsystem and is physically protected from ambient impurities. Therefore, Sb$_2$Te$_3$/Bi$_2$Te$_3$ heterojunctions can host robust helical interface states with promising spintronic applications.
description: 16 pages, 18 figures
Natural SU(2)-structures on tangent sphere bundles
Creators: name: Albuquerque, R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: FOS: Mathematics
subject: 53C15, 53C25, 53C44

description: We define and study natural $\mathrm{SU}(2)$-structures, in the sense of Conti-Salamon, on the total space $\cal S$ of the tangent sphere bundle of any given oriented Riemannian 3-manifold $M$. We recur to a fundamental exterior differential system of Riemannian geometry. Essentially, two types of structures arise: the contact-hypo and the non-contact and, for each, we study the conditions for being hypo, nearly-hypo or double-hypo. We discover new double-hypo structures on $S^3\times S^2$, of which the well-known Sasaki-Einstein are a particular case. Hyperbolic geometry examples also appear. In the search of the associated metrics, we find a theorem, useful for explicitly determining the metric, which applies to all $\mathrm{SU}(2)$-structures in general. Within our application to tangent sphere bundles, we discover a whole new class of metrics specific to 3d-geometry. The evolution equations of Conti-Salamon are considered; leading to a new integrable $\mathrm{SU}(3)$-structure on ${\cal S}\times\mathbb{R}_+$ associated to any flat $M$.
description: 27 pages, 1 figure, final version, accepted in The Asian Journal of Mathematics
Hydro-elastic Complementarity in Black Branes at large D
Creators: name: Emparan, Roberto
name: Izumi, Keisuke
name: Luna, Raimon
name: Suzuki, Ryotaku
name: Tanabe, Kentaro
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: We obtain the effective theory for the non-linear dynamics of black branes---both neutral and charged, in asymptotically flat or Anti-deSitter spacetimes---to leading order in the inverse-dimensional expansion. We find that black branes evolve as viscous fluids, but when they settle down they are more naturally viewed as solutions of an elastic soap-bubble theory. The two views are complementary: the same variable is regarded in one case as the energy density of the fluid, in the other as the deformation of the elastic membrane. The large-D theory captures finite-wavelength phenomena beyond the conventional reach of hydrodynamics. For asymptotically flat charged black branes (either Reissner-Nordstrom or p-brane-charged black branes) it yields the non-linear evolution of the Gregory-Laflamme instability at large D and its endpoint at stable non-uniform black branes. For Reissner-Nordstrom AdS black branes we find that sound perturbations do not propagate (have purely imaginary frequency) when their wavelength is below a certain charge-dependent value. We also study the polarization of black branes induced by an external electric field.
description: 26 pages. v2: 33 pages. Appendix added with a systematic derivation of the effective equations. v3: 34 pages. Expanded introduction
Eventually stable rational functions
Creators: name: Jones, Rafe
name: Levy, Alon
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: FOS: Mathematics
subject: 37P05 (primary), 37P15, 11R32, 12E05, 37P25 (secondary)

description: For a field K, rational function phi in K(z) of degree at least two, and alpha in P^1(K), we study the polynomials in K[z] whose roots are given by the solutions to phi^n(z) = alpha, where phi^n denotes the nth iterate of phi. When the number of irreducible factors of these polynomials stabilizes as n grows, the pair (phi, alpha) is called eventually stable over K. We conjecture that (phi, alpha) is eventually stable over K when K is any global field and alpha any point not periodic under phi (an additional non-isotriviality hypothesis is necessary in the function field case). We prove the conjecture when K has a discrete valuation for which (1) phi has good reduction and (2) phi acts bijectively on all finite residue extensions. As a corollary, we prove for these maps a conjecture of Sookdeo on the finiteness of S-integral points in backwards orbits. We also give several characterizations of eventual stability in terms of natural finiteness conditions, and survey previous work on the phenomenon.
description: 18 pages
Switching dynamics of morphology-structure in chemically deposited carbon films -a new insight
Creators: name: Ali, Mubarak
name: Urgen, Mustafa
Publisher: name: arXiv
Year: 2016
Subjects: subject: Materials Science (cond-mat.mtrl-sci)
subject: FOS: Physical sciences

description: Carbon is one of the most investigated materials and shows chaotic behavior in terms of evolving structure. Synthesizing carbon materials largely depend on the deposition technique, process parameters, condition of substrate surface and ratios of the gaseous chemistry. A variety of techniques have been employed to depositing carbon films from various gaseous mixtures to different substrate materials. In this study, carbon thin and thick films are discussed for different techniques known as hot filament chemical vapor deposition and microwave plasma chemical vapor deposition where their synthesis process has been explained in a new context. Here, we discuss attained dynamics of atoms or tiny grains amalgamating into a particular phase of grain or crystallite and electron-dynamics responsible for binding atoms in the formation of all sorts of tiny grains, grains and crystallites controlling overall morphology-structure of films thickness at few nanometers to several microns. Carbon atoms when in solid state, on amalgamation at flat surface result into bind under uniform electron-dynamics and when the amalgamation is at uneven surface, they result into bind under non-uniform electron-dynamics. Substrates under appropriate surface defects or abrasion result into an improved rate of nucleation of tiny grains, hence, their increased rate of growth. This study embarks on unexplored science of carbon films where in addition to localized process parameters nature of substrate also influence dynamics of formation of tiny clusters, grains and crystallites at their initial stage of formation. Our results and discussions enlighten us to revisit the nucleation and growth mechanisms of different sorts of films deposit at any scale and at any substrate surface constituting different composition.
Strengthened Reeh-Schlieder Property and Scattering in Quantum Field Theories without Mass Gaps
Creators: name: Duell, Maximilian
Publisher: name: arXiv
Year: 2016
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We develop Haag-Ruelle scattering theory for Wigner particles in local relativistic Quantum Field Theory without assuming mass gaps or any other restrictions on the spectrum of the mass operator near the particle masses. Our approach is based on the Reeh-Schlieder property of the vacuum state. It is shown that a strengthened variant of this property, concerning the relative approximation error for single-particle states, implies the existence of scattering states.
description: 27 pages, 1 figure, minor revisions, new appendix C. As appeared in Communications in Mathematical Physics
Students' epistemological framing in quantum mechanics problem solving
Creators: name: Modir, Bahar
name: Thompson, John D.
name: Sayre, Eleanor C
Publisher: name: arXiv
Year: 2016
Subjects: subject: Physics Education (physics.ed-ph)
subject: FOS: Physical sciences

description: Students' difficulties in quantum mechanics may be the result of unproductive framing and not a fundamental inability to solve the problems or misconceptions about physics content. We observed groups of students solving quantum mechanics problems in an upper-division physics course. Using the lens of epistemological framing, we investigated four frames in our observational data: algorithmic math, conceptual math, algorithmic physics, and conceptual physics. We discuss the characteristics of each frame as well as causes for transitions between different frames, arguing that productive problem solving may occur in any frame as long as students' transition appropriately between frames. Our work extends epistemological framing theory on how students frame discussions in upper-division physics courses.
description: Submitted to Physical Review -- Physics Education Research
Pure point diffraction and Poisson summation
Creators: name: Richard, Christoph
name: Strungaru, Nicolae
Publisher: name: arXiv
Year: 2015
Subjects: subject: Mathematical Physics (math-ph)
subject: FOS: Physical sciences

description: We prove that the diffraction formula for regular model sets is equivalent to the Poisson Summation Formula for the underlying lattice. This is achieved using Fourier analysis of unbounded measures on locally compact abelian groups as developed by Argabright and de Lamadrid. We also obtain diffraction results for certain classes of non-regular so-called weak model sets.
description: 24 pages, submitted
The category of $\mathbb{Z}_2^n$-supermanifolds
Creators: name: Covolo, Tiffany
name: Grabowski, Janusz
name: Poncin, Norbert
Publisher: name: arXiv
Year: 2016
Subjects: subject: Differential Geometry (math.DG)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 17A70, 58A50, 13F25, 16L30

description: In Physics and in Mathematics $\mathbb{Z}_2^n$-gradings, $n>1$, appear in various fields. The corresponding sign rule is determined by the `scalar product' of the involved $\mathbb{Z}_2^n$-degrees. The $\mathbb{Z}_2^n$-Supergeometry exhibits challenging differences with the classical one: nonzero degree even coordinates are not nilpotent, and even (resp., odd) coordinates do not necessarily commute (resp., anticommute) pairwise. In this article we develop the foundations of the theory: we define $\mathbb{Z}_2^n$-supermanifolds and provide examples in the ringed space and coordinate settings. We thus show that formal series are the appropriate substitute for nilpotency. Moreover, the class of $\mathbb{Z}_2^\bullet$-supermanifolds is closed with respect to the tangent and cotangent functors. We explain that any $n$-fold vector bundle has a canonical `superization' to a $\mathbb{Z}_2^n$-supermanifold and prove that the fundamental theorem describing supermorphisms in terms of coordinates can be extended to the $\mathbb{Z}_2^n$-context.
description: 18 pages. arXiv admin note: substantial text overlap with arXiv:1408.2755. Added references, added concluding remarks. To appear in Journal of Mathematical Physics
Constraints on cosmological viscosity and self interacting dark matter from gravitational wave observations
Creators: name: Goswami, Gaurav
name: Chakravarty, Girish Kumar
name: Mohanty, Subhendra
name: Prasanna, A. R.
Publisher: name: arXiv
Year: 2016
Subjects: subject: High Energy Physics - Phenomenology (hep-ph)
subject: Cosmology and Nongalactic Astrophysics (astro-ph.CO)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: It has been shown that gravitational waves propagate through ideal fluids without experiencing any dispersion or dissipation. However, if the medium has a non-zero shear viscosity $η$ , gravitational waves will be dissipated at a rate proportional to $G \,η$. We constrain dark matter and dark energy models with non-zero shear viscosity by calculating the dissipation of gravitational waves from GW150914 which propagate over a distance of $410\, $ Mpc through the dissipative fluid and comparing the data with the theoretical prediction. This provides a proof-of-principle demonstration of the fact that future observations gravitational waves at LIGO have the potential of better constraining the viscosity of dark matter and dark energy.
description: 6 pages, 2 figures. Journal version (to appear in Phy. Rev. D)
Unconventional superconductivity and anomalous response in hole-doped transition metal dichalcogenides
Creators: name: Sosenko, Evan
name: Zhang, Junhua
name: Aji, Vivek
Publisher: name: arXiv
Year: 2015
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: Two-dimensional transition metal dichalcogenides entwine interaction, spin-orbit coupling, and topology. Hole-doped systems lack spin degeneracy: states are indexed with spin and valley specificity. This unique structure offers new possibilities for correlated phases and phenomena. We realize an unconventional superconducting pairing phase which is an equal mixture of a spin singlet and the $m = 0$ spin triplet. It is stable against large in-plane magnetic fields, and its topology allows quasiparticle excitations of net nonzero Berry curvature via pair-breaking circularly polarized light.
description: 8 pages, 3 figures
Differentiability properties of Riesz potentials of finite measures and non-doubling Calderón-Zygmund theory
Creators: name: Cufí, Julià
name: Verdera, Joan
Publisher: name: arXiv
Year: 2016
Subjects: subject: Classical Analysis and ODEs (math.CA)
subject: FOS: Mathematics
subject: 42B20, 31B15, 26B05

description: We study differentiability properties of Riesz potentials of finite Borel measures in dimension d larger than 2. The Riesz kernel has homogeneity 2-d. In dimension 2 we consider logarithmic potentials. We introduce a notion of differentiability in the capacity sense, capacity being Newtonian capacity in dimension larger than 2 and Wiener capacity in the plane. It turns out that differentiability in the capacity sense at a point is related to the existence of principal values of the measure with respect to the vector valued Riesz potential x/|x|^d of homogeneity 1-d. This leads to Calderón-Zygmund theory for non-doubling measures. We prove that the Riesz potential of a finite Borel measure is differentiable in the capacity sense except for a set of zero C^1-harmonic capacity. This result is sharp. Surprisingly in the plane there are two distinct notions of differentiability in the capacity sense. For each of them we obtain the best possible result on the size of the exceptional set in terms of Hausdorff measures. We obtain for dimension larger than 2 results on Peano second order differentiability in the capacity sense with exceptional sets of zero Lebesgue measure. Finally, we apply our results to find a new proof of the fact that equilibrium measure is singular with respect to Lebesgue measure.
description: 43 pages. We added a new section with an application to the equilibrium measure. To appear in Annali Scuola Normale Superiore di Pisa
Phonon dispersions and Fermi surfaces nesting explaining the variety of charge ordering in titanium-oxypnictides superconductors
Creators: name: Nakano, Kosuke
name: Hongo, Kenta
name: Maezono, Ryo
Publisher: name: arXiv
Year: 2016
Subjects: subject: Superconductivity (cond-mat.supr-con)
subject: FOS: Physical sciences

description: There has been a puzzle between experiments and theoretical predictions on the charge ordering of layered titanium-oxypnictides superconductors. Unconventional mechanisms to explain this discrepancy have been argued so far, even affecting the understanding of superconductivity on the compound. We provide a new theoretical prediction, by which the discrepancy itself is resolved without any complicated unconventional explanation. Phonon dispersions and changes of nesting vectors in Fermi surfaces are clarified to lead to the variety of superlattice structures even for the common crystal structures when without CDW, including orthorhombic $2 \times 2 \times 1$ one for BaTi$_2$As$_2$O, which has not yet been explained successfully so far, being different from tetragonal $\sqrt{2} \times \sqrt{2} \times 1$ for BaTi$_2$Sb$_2$O and BaTi$_2$Bi$_2$O. The electronic structure analysis can naturally explain experimental observations about CDW including most latest ones without any cramped unconventional mechanisms.
description: Scientific Reports accepted
Ultrafast spin density wave transition in Chromium governed by thermalized electron gas
Creators: name: Nicholson, C. W.
name: Monney, C.
name: Carley, R.
name: Frietsch, B.
name: Bowlan, J.
name: Weinelt, M.
name: Wolf, M.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Strongly Correlated Electrons (cond-mat.str-el)
subject: FOS: Physical sciences

description: The energy and momentum selectivity of time- and angle-resolved photoemission spectroscopy is exploited to address the ultrafast dynamics of the antiferromagnetic spin density wave (SDW) transition photoexcited in epitaxial thin films of chromium. We are able to quantitatively extract the evolution of the SDW order parameter $Δ$ through the ultrafast phase transition. $Δ$ is defined by the transient temperature of the thermalized electron gas. The complete destruction of SDW order on a sub-100~fs time scale is observed, much faster than for conventional charge density wave materials. Our results reveal that equilibrium concepts for phase transitions such as the order parameter may be utilized even in the strongly non-adiabatic regime of ultrafast photo-excitation.
description: 7 pages, 7 figures
Renormalization of Horava Gravity
Creators: name: Barvinsky, Andrei O.
name: Blas, Diego
name: Herrero-Valea, Mario
name: Sibiryakov, Sergey M.
name: Steinwachs, Christian F.
Publisher: name: arXiv
Year: 2015
Subjects: subject: High Energy Physics - Theory (hep-th)
subject: General Relativity and Quantum Cosmology (gr-qc)
subject: FOS: Physical sciences

description: We prove perturbative renormalizability of projectable Horava gravity. The key element of the argument is the choice of a gauge which ensures the correct anisotropic scaling of the propagators and their uniform falloff at large frequencies and momenta. This guarantees that the counterterms required to absorb the loop divergences are local and marginal or relevant with respect to the anisotropic scaling. Gauge invariance of the counterterms is achieved by making use of the background-covariant formalism. We also comment on the difficulties of this approach when addressing the renormalizability of the non-projectable model.
description: 35 pages, no figures; references discussing gauge invariance of counterterms have been added, typos corrected
Binary Decision Diagrams for Random Boolean Functions
Creators: name: Gröpl, Clemens
Publisher: name: Humboldt-Universität zu Berlin, Mathematisch-Naturwissenschaftliche Fakultät II
Year: 1999
Subjects: subject: Binäres Entscheidungsdiagramm
subject: Boolesche Funktion
subject: probabilistische Analyse
subject: Shannon Effekt
subject: Binary decision diagram
subject: Boolean function
subject: probabilistic analysis
subject: Shannon effect
subject: 004 Informatik
subject: 28 Informatik, Datenverarbeitung
subject: SK 150

description: Binary Decision Diagrams (BDDs) sind eine Datenstruktur für Boolesche Funktionen, die auch unter dem Namen branching program bekannt ist. In ordered binary decision diagrams (OBDDs) müssen die Tests einer festen Variablenordnung genügen. In free binary decision diagrams (FBDDs) darf jede Variable höchstens einmal getestet werden. Die Effizienz neuer Varianten des BDD-Konzepts wird gewöhnlich anhand spektakulärer (worst-case) Beispiele aufgezeigt. Wir verfolgen einen anderen Ansatz und vergleichen die Darstellungsgrößen für fast alle Booleschen Funktionen. Während I. Wegener bewiesen hat, daß für die `meisten' n die erwartete OBDD-Größe einer zufälligen Booleschen Funktion von n Variablen gleich der worst-case Größe bis auf Terme kleinerer Ordnung ist, zeigen wir daß dies nicht der Fall ist für n innerhalb von Intervallen konstanter Länge um die Werte n = 2h + h. Ferner gibt es Bereiche von n, in denen minimale FBDDs fast immer um mindestens einen konstanten Faktor kleiner sind als minimale OBDDs. Unsere Hauptsätze ha ben doppelt exponentielle Wahrschein- lichkeitsschranken (in n). Außerdem untersuchen wir die Entwicklung zufälliger OBDDs und ihrer worst-case Größe und decken dabei ein oszillierendes Verhalten auf, das erklärt, warum gewisse Aussagen im allgemeinen nicht verstärkt werden können.
description: Binary Decision Diagrams (BDDs) are a data structure for Boolean functions which are also known as branching programs. In ordered binary decision diagrams (OBDDs), the tests have to obey a fixed variable ordering. In free binary decision diagrams (FBDDs), each variable can be tested at most once. The efficiency of new variants of the BDD concept is usually demonstrated with spectacular (worst-case) examples. We pursue another approach and compare the representation sizes of almost all Boolean functions. Whereas I. Wegener proved that for `most' values of n the expected OBDD size of a random Boolean function of n variables is equal to the worst-case size up to terms of lower order, we show that this is not the case for n within intervals of constant length around the values n = 2h + h. Furthermore, ranges of n exist for which minimal FBDDs are almost always at least a constant factor smaller than minimal OBDDs. Our main theorems have doubly exponentially small probability bounds (in n). We also investigate the evolution of random OBDDs and their worst-case size, revealing an oscillating behaviour that explains why certain results cannot be improved in general.
Eigenvalue vs perimeter in a shape theorem for self-interacting random walks
Creators: name: Biskup, Marek
name: Procaccia, Eviatar B.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Probability (math.PR)
subject: Mathematical Physics (math-ph)
subject: FOS: Mathematics
subject: FOS: Physical sciences
subject: 82B41, 60D05, 60F99

description: We study paths of time-length $t$ of a continuous-time random walk on $\mathbb Z^2$ subject to self-interaction that depends on the geometry of the walk range and a collection of random, uniformly positive and finite edge weights. The interaction enters through a Gibbs weight at inverse temperature $β$; the "energy" is the total sum of the edge weights for edges on the outer boundary of the range. For edge weights sampled from a translation-invariant, ergodic law, we prove that the range boundary condensates around an asymptotic shape in the limit $t\to\infty$ followed by $β\to\infty$. The limit shape is a minimizer (unique, modulo translates) of the sum of the principal harmonic frequency of the domain and the perimeter with respect to the first-passage percolation norm derived from (the law of) the edge weights. A dense subset of all norms in $\mathbb R^2$, and thus a large variety of shapes, arise from the class of weight distributions to which our proofs apply.
description: 31 pages, 1 figure, see arXiv:1603.03871 for a companion analysis paper, version to appear in Ann. Appl. Probab
Transitions in the cloud composition of hot Jupiters
Creators: name: Parmentier, Vivien
name: Fortney, Jonathan J.
name: Showman, Adam P.
name: Morley, Caroline V.
name: Marley, Mark S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Earth and Planetary Astrophysics (astro-ph.EP)
subject: Solar and Stellar Astrophysics (astro-ph.SR)
subject: FOS: Physical sciences

description: Over a large range of equilibrium temperatures, clouds shape the transmission spectrum of hot Jupiter atmospheres, yet their composition remains unknown. Recent observations show that the Kepler lightcurves of some hot Jupiters are asymmetric: for the hottest planets, the lightcurve peaks before secondary eclipse, whereas for planets cooler than $\sim1900\rm\,K$, it peaks after secondary eclipse. We use the thermal structure from 3D global circulation models to determine the expected cloud distribution and Kepler lightcurves of hot Jupiters. We demonstrate that the change from an optical lightcurve dominated by thermal emission to one dominated by scattering (reflection) naturally explains the observed trend from negative to positive offset. For the cool planets the presence of an asymmetry in the Kepler lightcurve is a telltale sign of the cloud composition, because each cloud species can produce an offset only over a narrow range of effective temperatures. By comparing our models and the observations, we show that the cloud composition of hot Jupiters likely varies with equilibrium temperature. We suggest that a transition occurs between silicate and manganese sulfide clouds at a temperature near $1600\rm\,K$, analogous to the L/T transition on brown dwarfs. The cold trapping of cloud species below the photosphere naturally produces such a transition and predicts similar transitions for other condensates, including TiO. We predict that most hot Jupiters should have cloudy nightsides, that partial cloudiness should be common at the limb and that the dayside hot spot should often be cloud-free.
description: Accepted for publication in ApJ. Revised version include effect of metallicity, CaTiO3 clouds, and models with an updated Al2O3 condensation curve. Conclusions are unchanged
Lower bounds for Maass forms on semisimple groups
Creators: name: Brumley, Farrell
name: Marshall, Simon
Publisher: name: arXiv
Year: 2016
Subjects: subject: Number Theory (math.NT)
subject: Analysis of PDEs (math.AP)
subject: FOS: Mathematics
subject: 35P20, 11F60

description: Let $G$ be an anisotropic semisimple group over a totally real number field $F$. Suppose that $G$ is compact at all but one infinite place $v_0$. In addition, suppose that $G_{v_0}$ is $\mathbb{R}$-almost simple, not split, and has a Cartan involution defined over $F$. If $Y$ is a congruence arithmetic manifold of non-positive curvature associated to $G$, we prove that there exists a sequence of Laplace eigenfunctions on $Y$ whose sup norms grow like a power of the eigenvalue.
US Cattle Traceability Information - State Government Web Information Resource Analysis
Creators: name: Boehm, Reid
Publisher: name: Open Science Framework
Year: 2022
Subjects: subject: agriculture
subject: beef cattle
subject: cattle identification
subject: cattle traceability
subject: content analysis
subject: egovernment
subject: science communication

description: This is a content analysis of state government cattle traceability information resources from all 50 states. I searched the state department of agriculture website and the cooperative extension website in each state for the first 10 records pertaining to cattle traceability (additional search terms were used to account for some of the discrepency in terminology) Information topics, types, formats, and elements of information quality were evaluated. The study used state-level demographic data from the NASS 2012 agriculture census to give a picture of the information needs of the cattle producers in the state. States were compared for their ability to provide information based on these information needs. Additionally, the study incorporated social network analysis of the external resources with which each state linked out to - to provide understanding of what information is common across certain states and whether states are sharing information or are in anyway connected via information resources.
title: Refugee Recognition Regime Country Profile: Kenya
Creators: name: Nalule, Caroline
Publisher: name: Hertie School
Year: 2023

description: This report discusses the evolution of the refugee recognition regime (RRR) in Kenya, chiefly over the period of 2000-2020. It highlights the government’s responses towards refugee protection, its bifurcated approach towards refugees based on where they reside, the challenges faced by protection seekers in the recognition process, and the shifts in responsibility between the government and UNHCR. The report is based on extensive desk-based research as well as original fieldwork, including interviews and focus group discussions with adult asylum seekers and refugees, as well as officers involved in refugee status determination (RSD) processes. The research targeted refugees and asylum seekers from the top four recognised nationalities in Kenya in the 20-year period: Somalis, South Sudanese, Ethiopians, and Congolese from the Democratic Republic of Congo (DRC).
Maximizing Truck Platooning Participation with a Focus on Privacy and Preference-Based Matching
Creators: name: Barua, Limon
Publisher: name: University of Illinois at Chicago
Year: 2023

description: Truck platooning refers to a group of trucks driving closely together, using advanced connected and automated driving technologies to reduce energy consumption, operating costs, and emissions. Additionally, platooning can optimize road space utilization, increase road capacity, and improve traffic safety. However, for platooning to be widely adopted, it is critical to attract as many trucks as possible to participate. The main obstacles to widespread platooning are a focus on the system's optimal outcome rather than individual utility, privacy concerns, and the challenge of matching trucks for platooning. To address these issues, this research proposes a preference-based truck matching system that considers the stability of platoons, which is influenced by truck preferences for platooning partners. This approach is scientifically intriguing and practical for the highly fragmented US trucking sector, where preferences for fuel savings and schedule coordination affect platoon formation. To safeguard trucks' information privacy, the research suggests a platoon matching system that enables each truck to encrypt its itinerary information before sending it to a two-cloud system that protects data and facilitates secure and private platoon formation. Furthermore, the research proposes a platform that can consider multiple route options from a truck to find platoon partners, increasing the likelihood of forming a platoon, especially when the number of participating trucks is low. The proposed systems are computationally efficient, scalable, and effective in increasing fuel savings.
title: Psychotherapie wirkt
title: Zugewandter Blick in die Zukunft einer modernen, kollaborativen Behandlung
Creators: name: Flückiger, Christoph
name: Willutzki, Ulrike
name: Grosse Holtforth, Martin
name: Wampold, Bruce Edward
Publisher: name: Universität Kassel
Year: 2024
Subjects: subject: Psychische Gesundheit
subject: Transtheoretische Wirkprinzipien
subject: Therapieerfolg
subject: Evidenzbasierte Praxis
subject: Legitimität
subject: mental health
subject: transtheoretical principles
subject: treatment outcome
subject: evidence-based practice
subject: legitimacy
subject: 150
subject: 300
subject: Psychotherapie
subject: Psychische Gesundheit
subject: Therapieerfolg
subject: Evidenz-basierte Medizin
subject: Legitimität

description: Gefördert im Rahmen des Projekts DEAL
Regularity of Villadsen algebras and characters on their central sequence algebras
Creators: name: Christensen, Martin S.
Publisher: name: arXiv
Year: 2016
Subjects: subject: Operator Algebras (math.OA)
subject: K-Theory and Homology (math.KT)
subject: FOS: Mathematics
subject: 46L05, 46L35 46L80

description: We show that if A is a simple Villadsen algebra of either the first type with seed space a finite dimensional CW complex, or of the second type, then $A$ absorbs the Jiang-Su algebra tensorially if and only if the central sequence algebra of A does not admit characters. Additionally, in a joint appendix with Joan Bosa, we show that the Villadsen algebra of the second type with infinite stable rank fails the Corona Factorization Property, thus providing the first example of a unital, simple, separable and nuclear $C^\ast$-algebra with a unique tracial state which fails to have this property.
description: 24 pages. Math. Scand., to appear