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The expansion of the Universe is the basis of modern cosmology. This chapter outlines the theory behind the expansion of the universe, including the cosmological principle, distances, velocities, and accelerations. We provide basic…

Cosmology and Nongalactic Astrophysics · Physics 2025-09-15 Tamara M. Davis

In this paper we will explore fundamental constraints on the evolution of certain symplectic subvolumes possessed by any Hamiltonian phase space. This research has direct application to optimal control and control of conservative mechanical…

Optimization and Control · Mathematics 2007-09-11 Jared M. Maruskin , Daniel J. Scheeres , Anthony M. Bloch

We review the present theoretical and numerical understanding of magnetic field amplification in cosmic large-scale structure, on length scales of galaxy clusters and beyond. Structure formation drives compression and turbulence, which…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-28 J. Donnert , F. Vazza , M. Brüggen , J. ZuHone

Spacetime foam is analyzed within the simplistic model of a set of scalar fields on a flat background. We suggest the formula for the path integral which allows to account for the all possible topologies of spacetime. We show that the…

General Relativity and Quantum Cosmology · Physics 2008-09-11 A. A. Kirillov , E. P. Savelova

We generalize to the case of compactified superstrings a construction given previously for critical superstrings of finite one loop amplitudes that are well-defined for all external momenta. The novel issues that arise for compactified…

High Energy Physics - Theory · Physics 2009-10-30 Gordon Chalmers

A consistent set of asymptotic conditions for higher spin gravity in three dimensions is proposed in the case of vanishing cosmological constant. The asymptotic symmetries are found to be spanned by a higher spin extension of the BMS3…

High Energy Physics - Theory · Physics 2013-09-09 Hernan A. Gonzalez , Javier Matulich , Miguel Pino , Ricardo Troncoso

We work out an effective theory of accelerated expansion to describe general phenomena of inflation and acceleration (dark energy) in the Universe. Our aim is to determine from theoretical grounds, in a physically-motivated and model…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Raul Jimenez , P. Talavera , Licia Verde

We provide arguments for the use of the rational form of unitarization, its relation with the diffraction peak shrinkage and asymptotics of the inelastic cross--section. The particular problems of the Regge model and the exponential form of…

High Energy Physics - Phenomenology · Physics 2022-06-23 S. M. Troshin , N. E. Tyurin

We discuss the cosmology of axion-scalar systems in asymptotic limits of type IIB/F-theory flux compactifications. These results allow us to test a putative extension of the Distance Conjecture in a dynamical setting, which posits that…

High Energy Physics - Theory · Physics 2026-05-12 Filippo Revello

We investigate asymptotic symmetries in flat backgrounds of dimension higher than or equal to four. For spin two we provide the counterpart of the extended BMS transformations found by Campiglia and Laddha in four-dimensional Minkowski…

High Energy Physics - Theory · Physics 2021-02-03 Andrea Campoleoni , Dario Francia , Carlo Heissenberg

Blob-filaments (or simply 'blobs') are coherent structures formed by turbulence and sustained by nonlinear processes in the edge and scrape-off layer (SOL) of tokamaks and other magnetically confined plasmas. The dynamics of these…

Plasma Physics · Physics 2023-07-26 J. R. Myra , J. Cheng , S. E. Parker

Standard quantum field theory arguments predict an enormous cosmological constant. But what would this mean observationally? For a homogeneous universe the answer is clear, but if the universe is inhomogeneous at the Planck scale, the…

General Relativity and Quantum Cosmology · Physics 2025-10-30 Steven Carlip

In this report we obtain higher order asymptotic expansions of solutions to wave equations with frictional and viscoelastic damping terms. Although the diffusion phenomena are dominant, differences between the solutions we deal with and…

Analysis of PDEs · Mathematics 2018-07-27 Ryo Ikehata , Hironori Michihisa

We investigate the effects of cosmological expansion on the spectrum of small-scale structure on a cosmic string. We simulate the evolution of a string with two modes that differ in wavelength by one order of magnitude. Once the short mode…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Christian Stephan-Otto , Ken D. Olum , Xavier Siemens

We examine the structure of winding toroidal and open cylindrical membranes, especially in cases where they are stretched between boundaries. Non-zero winding or stretching means that there are linear terms in the mode expansion of the…

High Energy Physics - Theory · Physics 2016-09-06 Martin Cederwall

We explore the possibility that our universe's current accelerated expansion is explained by a quintessence model with an exponential scalar potential, $V =V_0\, e^{-\lambda\, \phi}$, keeping an eye towards $\lambda \geq \sqrt{2}$ and an…

High Energy Physics - Theory · Physics 2024-08-21 David Andriot , Susha Parameswaran , Dimitrios Tsimpis , Timm Wrase , Ivonne Zavala

So far spin foam models are hardly understood beyond a few of their basic building blocks. To make progress on this question, we define analogue spin foam models, so called spin nets, for quantum groups $\text{SU}(2)_k$ and examine their…

General Relativity and Quantum Cosmology · Physics 2014-08-06 Bianca Dittrich , Mercedes Martin-Benito , Sebastian Steinhaus

We show that the combination of a fluid with a bulk dissipative pressure and quintessence matter can simultaneously drive an accelerated expansion phase and solve the coincidence problem of our current Universe. We then study some scenarios…

Astrophysics · Physics 2009-10-31 Luis P. Chimento , Alejandro S. Jakubi , Diego Pavon

We consider solutions to the Lam\'e system in two dimensions. By using systematic way, based on layer potential techniques and the field expansion (FE) method (formal derivation), we establish a rigorous asymptotic expansion for the…

Analysis of PDEs · Mathematics 2017-06-28 Jihene Lagha , Faouzi Triki , Habib Zribi

Understanding how frustration and disorder shape relaxation in complex systems is a central problem in statistical physics and quantum annealing. Spin-glass models provide a natural framework to explore this connection, as their energy…

Statistical Mechanics · Physics 2025-10-30 Viviana Gómez , Gabriel Téllez , Fernando J. Gómez-Ruiz