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Related papers: New Exponential and Polynomial $\xi$-attractors

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We introduce a new family of multiple orthogonal polynomials satisfying orthogonality conditions with respect to two weights $(w_1,w_2)$ on the positive real line, with $w_1(x)=x^\alpha e^{-x}$ the gamma density and $w_2(x) = x^\alpha…

Classical Analysis and ODEs · Mathematics 2023-08-15 Walter Van Assche , Thomas Wolfs

We introduce the new concepts of pseu\-do numerical range for operator functions and families of sesquilinear forms as well as the pseu\-do block numerical range for $n \times n$ operator matrix functions. While these notions are new even…

Spectral Theory · Mathematics 2023-01-04 Borbala Gerhat , Christiane Tretter

We consider a broad class of inflationary models of two unconstrained chiral superfields, the stabilizer $S$ and the inflaton $\Phi$, which can describe inflationary models with nearly arbitrary potentials. These models include, in…

High Energy Physics - Theory · Physics 2016-11-09 Andrei Linde

In the scalar-tensor theory of gravitation it seems nontrivial to establish if solutions of the cosmological equations in the presence of a cosmological constant behave as attractors independently of the initial values. We develop a general…

High Energy Physics - Theory · Physics 2009-11-06 Kei-ichi Maeda , Yasunori Fujii

There is a generalized oscillator-like algebra associated with every class of orthogonal polynomials $\{\Psi_n(x)\}_{n=0}^{\infty}$, on the real line, satisfying a four term non-symmetric recurrence relation…

Mathematical Physics · Physics 2017-09-11 G. Honnouvo , K. Thirulogasanthar

By using the relations between the slow-roll parameters and the power spectrum for the single field slow-roll inflation, we derive the scalar spectral tilt $n_s$ and the tensor to scalar ratio $r$ for the constant slow-roll inflation and…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 Qing Gao

This note concerns the problem of minimizing a certain family of non-local energy functionals over measures on $\mathbb{R}^n$, subject to a mass constraint, in a strong attraction limit. In these problems, the total energy is an integral…

Analysis of PDEs · Mathematics 2020-03-05 Almut Burchard , Rustum Choksi , Elias Hess-Childs

We consider D-term hybrid inflation in the framework of superconformal supergravity. In part of the parameter space, inflation continues for subcritical inflaton field value. Consequently, a new type of inflation emerges, which gives…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-04 Koji Ishiwata

We consider a general class of quantum gravity-inspired, modified gravity theories, where the Einstein-Hilbert action is extended through the addition of all terms quadratic in the curvature tensor coupled to scalar fields with standard…

General Relativity and Quantum Cosmology · Physics 2016-04-12 Kent Yagi , Leo C. Stein , Nicolas Yunes , Takahiro Tanaka

The Einstein-Maxwell fields of rotating stationary sources are represented by the SU(2,1) spinor potential $\Psi_A$ satisfying \[ \nabla \cdot [\Theta ^{-1}(\Psi_A\nabla \Psi_B-\Psi_B\nabla \Psi_A)]=-2\Theta ^{-2}\vec{C}\cdot (\Psi_A\nabla…

General Relativity and Quantum Cosmology · Physics 2016-08-31 Zoltán Perjés

We consider a linear implicit-explicit (IMEX) time discretization of the Cahn-Hilliard equation with a source term, endowed with Dirichlet boundary conditions. For every time step small enough, we build an exponential attractor of the…

Numerical Analysis · Mathematics 2023-08-24 Dieunel Dor , Morgan Pierre

In this work we introduce the concept of generalized exponential $\mathfrak{D}$-pullback attractor for evolution processes, where $\mathfrak{D}$ is a universe of families in $X$, which is a compact and positively invariant family that…

Dynamical Systems · Mathematics 2024-01-15 Matheus C. Bortolan , Tomas Caraballo , Carlos Pecorari Neto

We consider vacuum anisotropic spatially homogeneous models in certain modified gravity theories (such as Ho\v{r}ava-Lifshitz, $\lambda$-$R$ or $f(R)$ gravity), which are expected to describe generic spacelike singularities for these…

General Relativity and Quantum Cosmology · Physics 2026-03-16 Ester Beatriz , Everaldo Bonotto , Phillipo Lappicy

A solution for the Einstein gravity coupled with non linear electrodynamics is introduced in 2+1 dimensions. Especially, in the case with a non-vanishing cosmological constant, we obtain a novel black hole solution. To find fundamental…

General Relativity and Quantum Cosmology · Physics 2013-12-11 M. Kuniyasu

Utilizing the autonomous system of ordinary differential equations derived in arXiv:1809.01458 to define the evolution, we further investigate a class of cosmological models within an Einstein-aether gravitational framework by introducing a…

General Relativity and Quantum Cosmology · Physics 2024-02-28 S. Mohandas , R. J. van den Hoogen , D. Winters , M. Dala

The possibility of the extension of spatial diffeomorphisms to a larger family of symmetries in a class of classical field theories is studied. The generator of the additional local symmetry contains a quadratic kinetic term and a potential…

High Energy Physics - Theory · Physics 2015-05-18 Szilard Farkas , Emil J. Martinec

We study an inflation mechanism based on attractor properties in cosmological evolutions of a spatially flat Friedmann-Robertson-Walker spacetime based on the Einstein-scalar field theory. We find a new way to get the Hamilton-Jacobi…

General Relativity and Quantum Cosmology · Physics 2013-12-10 Hyeong-Chan Kim

We propose a 3 + 1 dimensional model of gravity which results in inflation at early times, followed by radiation- and matter-dominated epochs and a subsequent acceleration at late times. Both the inflation and late time acceleration are…

High Energy Physics - Theory · Physics 2015-05-30 Carlos Herdeiro , Shinji Hirano

We obtain a new 3D gravity model from two copies of parity-odd Einstein-Cartan theories. Using Hamiltonian analysis, we demonstrate that the only local degrees of freedom are two massive spin-2 modes. Unitarity of the model in anti-de…

High Energy Physics - Theory · Physics 2019-07-19 Mehmet Ozkan , Yi Pang , Utku Zorba

We propose a new exponential f(R) gravity model with f(R)=(R-\lambda c)e^{\lambda(c/R)^n} and n>3, \lambda\geq 1, c>0 to explain late-time acceleration of the universe. At the high curvature region, the model behaves like the \LambdaCDM…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Qiang Xu , Bin Chen