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Related papers: The existence of smooth solutions in q-theories

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The Cauchy problem for a quasilinear system of hyperbolic equations describing plane one-dimensional relativistic oscillations of electrons in a cold plasma is considered. For some simplified formulation of the problem, a criterion for the…

Mathematical Physics · Physics 2021-01-08 Olga S. Rozanova , Eugeniy V. Chizhonkov

We find a representation of smooth solutions to the Cauchy problem for a scalar multidimensional conservation law as small diffusion limit of a stochastic perturbation along characteristics. It helps, in particular, to study the process of…

Analysis of PDEs · Mathematics 2012-10-11 S. Albeverio , O. Rozanova

In this paper, we present an analytical study, in the one space dimensional case, of the fluid dynamics system proposed in [4] to model the formation of biofilms. After showing the hyperbolicity of the system, we show that, in a open…

Analysis of PDEs · Mathematics 2015-06-05 Roberta Bianchini , Roberto Natalini

One of the major problems in the theory of the porous medium equation is the regularity of the solutions and the free boundaries. Here we assume flatness of the solution in space time cylinder and derive smoothness of the interface after a…

Analysis of PDEs · Mathematics 2016-09-29 Clemens Kienzler , Herbert Koch , Juan Luis Vazquez

Based on the assertion that the cosmological constant problem is essentially a quantum gravity problem, the framework which addresses the cosmological constant problem should also bear a picture for the ``quantum space-time''. In this talk…

High Energy Physics - Phenomenology · Physics 2009-10-07 M. M. Sheikh-Jabbari

A class of non-strictly hyperbolic systems of quasilinear equations with oscillatory solutions of the Cauchy problem, globally smooth in time in some open neighborhood of the zero stationary state, is found. For such systems, the period of…

Analysis of PDEs · Mathematics 2024-12-31 Olga Rozanova

We consider the Cauchy problem of systems of quasilinear wave equations in 2-dimensional space. We assume that the propagation speeds are distinct and that the nonlinearities contain quadratic and cubic terms of the first and second order…

Analysis of PDEs · Mathematics 2017-06-29 Akira Hoshiga

The initial value problem is well-defined on a class of spacetimes broader than the globally hyperbolic geometries for which existence and uniqueness theorems are traditionally proved. Simple examples are the time-nonorientable spacetimes…

General Relativity and Quantum Cosmology · Physics 2007-05-23 John L. Friedman

One possible solution of the cosmological constant problem involves a so-called $q$-field, which self-adjusts so as to give a vanishing gravitating vacuum energy density (cosmological constant) in equilibrium. We show that this $q$-field…

High Energy Physics - Theory · Physics 2017-06-21 F. R. Klinkhamer , G. E. Volovik

This paper concerns the so-called cosmological constant problem. In order to solve it, we propose a toy model providing an extension of the dimensionality of spacetime, with an additional spatial dimension which is macroscopically…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Wojciech P. Tarkowski

In terms of initial data, a sufficient condition for the smoothness of the solution to the Cauchy problem for one-dimensional relativistic cold plasma equations over any given time interval is found. Unlike the non-relativistic case, such…

Mathematical Physics · Physics 2025-10-21 Olga S. Rozanova , Evgeniy V. Chizhonkov

This paper focuses on Cauchy problem for the three-dimensional two-fluid type model, in which the presence of vacuum is permitted. Under some assumptions that the initial data satisfy appropriate regularity conditions and a compatibility…

Analysis of PDEs · Mathematics 2026-01-27 Huanyao Wen , Chanxin Xie

Big Bang models of the Universe predict rapid domination by curvature, a paradox known as the flatness problem. Solutions to this problem usually leave the Universe exactly flat for every practical purpose. Explaining a nearly but not…

Astrophysics · Physics 2009-10-31 John D. Barrow , Joao Magueijo

We study the Cauchy problem for multi-dimensional compressible radiation hydrodynamics equations with vacuum. First, we present some sufficient conditions on the blow-up of smooth solutions in multi-dimensional space. Then, we obtain the…

Mathematical Physics · Physics 2014-01-14 Yachun Li , Shengguo Zhu

We study the stability of cosmological scaling solutions within the class of spatially homogeneous cosmological models with a perfect fluid subject to the equation of state p_gamma=(gamma-1) rho_gamma (where gamma is a constant satisfying 0…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. P. Billyard , A. A. Coley , R. J. van den Hoogen

In this work we deal with non-topological solutions of the Q-ball type in two space-time dimensions, in models described by a single complex scalar field that engenders global symmetry. The main novelty is the presence of stable Q-balls…

High Energy Physics - Theory · Physics 2016-05-24 D. Bazeia , L. Losano , M. A. Marques , R. Menezes , R. da Rocha

We consider a class of abstract nonlinear evolution equations in supermanifolds (smf's) modelled over Z_2-graded locally convex spaces. We show uniqueness, local existence, smoothness, and an abstract version of causal propagation of the…

High Energy Physics - Theory · Physics 2008-02-03 Thomas Schmitt

It will be argued here that the cosmological constant problem exists because of the way the vacuum is defined in quantum field theory. It has been known for some time that for QFT to be gauge invariant certain terms--such as part of the…

General Relativity and Quantum Cosmology · Physics 2008-06-20 Gerald E. Marsh

The $q$-theory formalism aims to describe the thermodynamics and dynamics of the deep quantum vacuum. The thermodynamics leads to an exact cancellation of the quantum-field zero-point-energies in equilibrium, which partly solves the main…

High Energy Physics - Theory · Physics 2017-10-25 F. R. Klinkhamer , M. Savelainen , G. E. Volovik

We prove that for large enough data, the life span of smooth solutions to the Cauchy problem for the following two quasilinear hyperbolic systems is finite: (1) equations of relativistic compressible fluid dynamics, (2) equations of plasma…

Analysis of PDEs · Mathematics 2007-05-23 Yan Guo , A. Shadi Tahvildar-Zadeh
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