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Related papers: Limits on a Dynamically Varying Fine Structure Con…

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Motivated by the Dirac idea that fundamental constant are dynamical variables and by conjectures on quantum structure of spacetime at small distances, we consider the possibility that Planck constant $\hbar$ is a time depending quantity,…

Quantum Physics · Physics 2015-12-16 Gianpiero Mangano , Fedele Lizzi , Alberto Porzio

We study the $\Lambda(\alpha)$CDM models with $\Lambda(\alpha)$ being a function of the time-varying fine structure constant $\alpha$. We give a close look at the constraints on two specific $\Lambda(\alpha)$CDM models with one and two…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-13 Jin-Jun Zhang , Lu Yin , Chao-Qiang Geng

We analyze different data of the variation of the fine structure constant obtained with different methods to check their consistency.We test consistency using the modified Student test and confidence intervals. We split the data sets in…

Astrophysics · Physics 2009-11-13 Susana J. Landau , Claudio Simeone

In this paper, we consider the dynamics of integrable stochastic Hamiltonian systems. Utilizing the Nagaev-Guivarc'h method, we obtain several generalized results of the central limit theorem. Making use of this technique and the Birkhoff…

Dynamical Systems · Mathematics 2024-04-04 Chen Wang , Yong Li

This paper presents an $hp$ a posteriori error analysis for the 2D Helmholtz equation that is robust in the polynomial degree $p$ and the wave number $k$. For the discretization, we consider a discontinuous Galerkin formulation that is…

Numerical Analysis · Mathematics 2019-01-31 Scott Congreve , Joscha Gedicke , Ilaria Perugia

We discuss the utility of low-lying Dirac eigenmodes for studying the nature of topological charge fluctuations in QCD. The implications of previous results using the local chirality histogram method are discussed, and the new results using…

High Energy Physics - Lattice · Physics 2008-11-26 S. J. Dong , T. Draper , I. Horvath , N. Isgur , F. X. Lee , J. McCune , J. B. Zhang , H. B. Thacker

A non-perturbative determination of the axial current improvement coefficient cA is performed with two flavors of dynamical improved Wilson fermions and plaquette gauge action. The improvement condition is formulated with Schroedinger…

High Energy Physics - Lattice · Physics 2008-11-26 Michele Della Morte , Roland Hoffmann , Rainer Sommer

Non-leptonic kaon decays are often described through an effective chiral weak Hamiltonian, whose couplings ("low-energy constants") encode all non-perturbative QCD physics. It has recently been suggested that these low-energy constants…

High Energy Physics - Lattice · Physics 2010-02-03 P. Hernandez , M. Laine

We study the nature of the phase transition in the multifractal formalism of the harmonic measure of Diffusion Limited Aggregates (DLA). Contrary to previous work that relied on random walk simulations or ad-hoc models to estimate the low…

Statistical Mechanics · Physics 2007-05-23 Mogens H. Jensen , Anders Levermann , Joachim Mathiesen , Benny Davidovitch , Itamar Procaccia

We explore the potential variation of two fundamental constants, the fine-structure constant $\alpha$ and the proton-to-electron mass ratio $\mu$, within the framework of modified gravity theories and finite-temperature effects. Utilising…

Solar and Stellar Astrophysics · Physics 2025-09-17 Akhil Uniyal , Surajit Kalita , Yosuke Mizuno , Sayan Chakrabarti , Yan Lu

We present a refined and improved study of the influence of screening on the effective fine structure constant of graphene, $\alpha^*$, as measured in graphite using inelastic x-ray scattering. This follow-up to our previous study [J. P.…

Strongly Correlated Electrons · Physics 2016-06-01 Yu Gan , Gilberto de la Pena Munoz , Anshul Kogar , Bruno Uchoa , Diego Casa , Thomas Gog , Eduardo Fradkin , Peter Abbamonte

In this paper, we consider a Diophantine quasi-periodic time-dependent analytic perturbation of a convex integrable Hamiltonian system, and we prove a result of stability of the action variables for an exponentially long interval of time.…

Dynamical Systems · Mathematics 2015-06-23 Abed Bounemoura

Over a period of eight months, we have monitored transition frequencies between nearly degenerate, opposite-parity levels in two isotopes of atomic dysprosium (Dy). These transition frequencies are highly sensitive to temporal variation of…

Atomic Physics · Physics 2008-11-26 A. Cingoz , A. Lapierre , A. -T. Nguyen , N. Leefer , D. Budker , S. K. Lamoreaux , J. R. Torgerson

We derive a nearly optimal upper bound on the running time in the adiabatic theorem for a switching family of Hamiltonians. We assume the switching Hamiltonian is in the Gevrey class $G^\alpha$ as a function of time, and we show that the…

Mathematical Physics · Physics 2015-06-04 Alexander Elgart , George A. Hagedorn

We study the asymptotic behavior of solutions to a monostable integro-differential Fisher-KPP equation , that is where the standard Laplacian is replaced by a convolution term, when the dispersal kernel is fat-tailed. We focus on two…

Analysis of PDEs · Mathematics 2018-04-23 Emeric Bouin , Jimmy Garnier , Christopher Henderson , Florian Patout

Theories unifying gravity with other interactions suggest spatial and temporal variation of fundamental ``constants'' in the Universe. A change in the fine structure constant, alpha, could be detected via shifts in the frequencies of atomic…

We adapt a finite difference method of solution of the two-dimensional massless Dirac equation, developed in the context of lattice gauge theory, to the calculation of electrical conduction in a graphene sheet or on the surface of a…

Mesoscale and Nanoscale Physics · Physics 2009-01-02 J. Tworzydlo , C. W. Groth , C. W. J. Beenakker

Neutron diffraction is used to examine the polarization of weak static antiferromagnetism in high quality single crystalline URu2Si2. As previously documented, elastic Bragg-like diffraction develops for temperature T<T_{HO}= 17.5 K at…

Strongly Correlated Electrons · Physics 2015-06-18 K. A. Ross , L. Harriger , Z. Yamani , W. J. L. Buyers , J. D. Garrett , A. A. Menovsky , J. A. Mydosh , C. L. Broholm

Radio-frequency E1 transitions between nearly degenerate, opposite parity levels of atomic dysprosium were monitored over an eight month period to search for a variation in the fine-structure constant. During this time period, data were…

Dirac-like Hamiltonians, linear in momentum $k$, describe the low-energy physics of a large set of novel materials, including graphene, topological insulators, and Weyl fermions. We show here that the inclusion of a minimal $k^2$ Wilson's…

Mesoscale and Nanoscale Physics · Physics 2021-12-06 A. L. Araújo , R. P. Maciel , R. G. F. Dornelas , D. Varjas , G. J. Ferreira
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