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We perform a rigorous analysis of the anelastic approximation for the Gross-Pitaevskii equation with $x$-dependent chemical potential. For general initial data and periodic boundary condition, we show that as $\eps\to 0$, equivalently the…

Analysis of PDEs · Mathematics 2015-12-02 Chi-Kun Lin , Kung-Chien Wu

In this work, two fast multipole boundary element formulations for the linear time-harmonic acoustic analysis of finite periodic structures are presented. Finite periodic structures consist of a bounded number of unit cell replications in…

Numerical Analysis · Mathematics 2022-01-31 Christopher Jelich , Wenchang Zhao , Haibo Chen , Steffen Marburg

Accurate simulation of nonlinear acoustic waves is essential for the continued development of a wide range of (high-intensity) focused ultrasound applications. This article explores mixed finite element formulations of classical strongly…

Numerical Analysis · Mathematics 2022-09-08 Mostafa Meliani , Vanja Nikolić

We present new constraints on the rest-frame sound speed, c_{eff}^2, and the viscosity parameter, c_{vis}^2, of the Cosmic Neutrino Background from the recent measurements of the Cosmic Microwave Background anisotropies provided by the…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Martina Gerbino , Eleonora Di Valentino , Najla Said

It is shown that the usual choice of units obtained by taking G = c = Planck constant = 1, giving the Planck units of mass, length and time, introduces an artificial contradiction between cosmology and particle physics: the lambda problem…

General Physics · Physics 2009-04-17 Antonio Alfonso-Faus

Extending the commutator algebra of quantum $\kappa$-Poincar\'e symmetry to the whole of the phase space, and assuming that this algebra is to be covariant under action of deformed Lorentz generators, we derive the transformation properties…

High Energy Physics - Theory · Physics 2009-11-07 J. Kowalski-Glikman

Cosmological constraints on the scalar-tensor theory of gravity by analyzing the angular power spectrum data of the cosmic microwave background (CMB) obtained from the Planck 2015 results are presented. We consider the harmonic attractor…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-08 Junpei Ooba , Kiyotomo Ichiki , Takeshi Chiba , Naoshi Sugiyama

It is discussed that the classical effective medium theory for the elastic properties of random heterogeneous materials is not congruous with the effective medium theory for the electrical conductivity. In particular, when describing the…

Materials Science · Physics 2020-02-17 Snarskii Andrei , Shamonin Mikhail , Yuskevich Pavel

The properties of asymmetric nuclear matter have been investigated in a relativistic Dirac-Brueckner-Hartree-Fock framework using the Bonn A potential. The components of the self-energies are extracted by projecting on Lorentz invariant…

Nuclear Theory · Physics 2009-11-10 E. N. E. van Dalen , C. Fuchs , Amand Faessler

We present an implementation of the analytical string theory recently applied to the description of glasses. These are modeled as continuum media with embedded elastic string heterogeneities, randomly located and randomly oriented, which…

Materials Science · Physics 2020-05-27 Ernesto Bianchi , Valentina M. Giordano , Fernando Lund

We present a semi-analytical theory for the acoustic fields and particle-trapping forces in a viscous fluid inside a capillary tube with arbitrary cross section and ultrasound actuation at the walls. We find that the acoustic fields vary…

Fluid Dynamics · Physics 2020-02-26 Jacob S. Bach , Henrik Bruus

We study Planck 2015 cosmic microwave background (CMB) anisotropy data using the energy density inhomogeneity power spectrum generated by quantum fluctuations during an early epoch of inflation in the non-flat XCDM model. Here dark energy…

Cosmology and Nongalactic Astrophysics · Physics 2018-12-19 Junpei Ooba , Bharat Ratra , Naoshi Sugiyama

The Plebanski-Demianski metric, and those that can be obtained from it by taking coordinate transformations in certain limits, include the complete family of space-times of type D with an aligned electromagnetic field and a possibly…

General Relativity and Quantum Cosmology · Physics 2009-11-11 J. B. Griffiths , J. Podolsky

Theoretical frameworks used to qualitatively and quantitatively describe nuclear dynamics in solids are often based on the harmonic approximation. However, this approximation is known to become inaccurate or to break down completely in many…

Materials Science · Physics 2020-09-02 Florian Knoop , Thomas A. R. Purcell , Matthias Scheffler , Christian Carbogno

We consider the possible existence of gravitationally bound general relativistic strings consisting of Bose-Einstein condensate (BEC) matter which is described, in the Newtonian limit, by the zero temperature time-dependent nonlinear…

General Relativity and Quantum Cosmology · Physics 2015-09-29 Tiberiu Harko , Matthew J. Lake

The paper is devoted to the description a measurable time-interval (``proper time'') in the Hamiltonian version of general relativity with the Dirac-ADM metric. To separate the dynamical parameter of evolution from the space metric we use…

General Relativity and Quantum Cosmology · Physics 2014-11-17 L. N. Gyngazov , M. Pawlowski , V. N. Pervushin , V. I. Smirichinski

A real aether model of the vacuum proposed by Allen Rothwarf based upon a degenerate Fermion fluid of polarizable particle-antiparticle pairs, leads to a big bang model of the universe where the velocity of light varies inversely with the…

Astrophysics · Physics 2007-05-23 Frederick Rothwarfs , Sisir Roy

Metric mean dimension is a geometric invariant of dynamical systems with infinite topological entropy. We relate this concept with the fractal structure of the phase space and the H\"older regularity of the map. Afterwards we improve our…

Dynamical Systems · Mathematics 2025-05-29 Alexandre Baraviera , Maria Carvalho , Gustavo Pessil

Recently, the Planck collaboration has released the first cosmological papers providing the highest resolution, full sky, maps of the cosmic microwave background (CMB) temperature anisotropies. In this paper we study a phenomenological…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-05 Hong Li , Jun-Qing Xia