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Conformally compactified phase space is conceived as an automorphism space for the global action of the extended conformal group. Space time and momentum space appear then as conformally dual, that is conjugate with respect to conformal…

High Energy Physics - Theory · Physics 2007-05-23 Paolo Budinich

The phase space analysis of cosmological parameters $\Omega_{\phi}$ and $\gamma_{\phi}$ is given. Based on this, the well-known quintessence cosmology is studied with an exponential potential $V(\phi)=V_{0}\exp(-\lambda\phi)$. Given…

General Relativity and Quantum Cosmology · Physics 2016-06-14 Jing-Zhao Qi , Ming-Jian Zhang , Wen-Biao Liu

The frame-dragging phenomenon in gravitational fields is revisited to explore the geometric effects induced by spacetime curvature. We quantize a massless scalar field in the spacetime of a rotating sphere, incorporating the frame-dragging…

General Relativity and Quantum Cosmology · Physics 2024-08-26 Rui-Chen Liu , C. P. Sun

We derive generic equations for a vector field driving the evolution of flat homogeneous isotropic universe and give a comparison with a scalar filed dynamics in the cosmology. Two exact solutions are shown as examples, which can serve to…

General Relativity and Quantum Cosmology · Physics 2009-11-10 V. V. Kiselev

How can one fully harness the power of physics encoded in relativistic $N$-body phase space? Topologically, phase space is isomorphic to the product space of a simplex and a hypersphere and can be equipped with explicit coordinates and a…

High Energy Physics - Phenomenology · Physics 2024-08-26 Tianji Cai , Junyi Cheng , Nathaniel Craig , Giacomo Koszegi , Andrew J. Larkoski

Spacetime foam manifests itself in a variety of ways. It has some attributes of a turbulent fluid. It is the source of the holographic principle. Cosmologically it may play a role in explaining why the energy density has the critical value,…

General Relativity and Quantum Cosmology · Physics 2011-02-24 Y. Jack Ng

We consider scalar perturbations of energy-density for a class of cosmological models where an early phase of accelerated expansion evolves, without any fine-tuning for graceful exit, towards the standard Friedman eras of observed universe.…

General Relativity and Quantum Cosmology · Physics 2011-05-10 S. Capozziello , G. Lambiase , G. Scarpetta

We give a new definition, based on considerations of well-posedness for a certain asymptotic initial value problem, of the phase space for the radiative degrees of freedom of the gravitational field in exact General Relativity. This space…

General Relativity and Quantum Cosmology · Physics 2010-11-01 Adam D. Helfer

We consider the two-dimensional (2D) flow in a flat free-slip surface that bounds a three-dimensional (3D) volume in which the flow is turbulent. The equations of motion for the two-dimensional flow in the surface are neither compressible…

Chaotic Dynamics · Physics 2009-11-07 Bruno Eckhardt , Joerg Schumacher

We calculate the vacuum energy density by taking account of different massive scalar fields in AdS spacetime. It is found that the mass spectrum of a scalar field in AdS spacetime is discrete because of a natural boundary condition. The…

Astrophysics · Physics 2009-11-06 Zhe Chang , Xin-Bing Huang

The symmetron is a scalar field associated with the dark sector whose coupling to matter depends on the ambient matter density. The symmetron is decoupled and screened in regions of high density, thereby satisfying local constraints from…

Cosmology and Nongalactic Astrophysics · Physics 2011-11-23 Kurt Hinterbichler , Justin Khoury , Aaron Levy , Andrew Matas

We propose the Proxemic Floor Field Model as an extension of the Floor Field Model, which is one of the successful models describing the pedestrian dynamics. Proxemic Floor Field is the Floor Field which corresponds to the effect of…

Physics and Society · Physics 2012-07-16 Takahiro Ezaki , Daichi Yanagisawa , Kazumichi Ohtsuka , Katsuhiro Nishinari

This paper introduces the trajectory divergence rate, a scalar field which locally gives the instantaneous attraction or repulsion of adjacent trajectories. This scalar field may be used to find highly attracting or repelling invariant…

Chaotic Dynamics · Physics 2019-04-10 Gary K. Nave, , Peter J. Nolan , Shane D. Ross

We examine models in which the accelerated expansion of the universe is driven by a scalar field rolling near an inflection point in the potential. For the simplest such models, in which the potential is of the form V(\phi) = V_0 + V_3…

Cosmology and Nongalactic Astrophysics · Physics 2013-10-30 Hui-Yiing Chang , Robert J. Scherrer

We investigate time dependent solutions (S-brane solutions) for product manifolds consisting of factor spaces where only one of them is non-Ricci-flat. Our model contains minimally coupled free scalar field as a matter source. We discuss a…

High Energy Physics - Theory · Physics 2009-11-11 Viktor Baukh , Alexander Zhuk

An action principle for spacetimes with the topology of an Euclidean black-hole is given. The gravitational field is described by the ordinary volume degrees of freedom plus additional surface fields at the horizon. The surface degrees of…

High Energy Physics - Theory · Physics 2009-12-30 Claudio Teitelboim

In this paper, we develop the general formalism and properties of the spacetime density matrix, which captures correlations among different Cauchy surfaces and can be regarded as a natural generalization of the standard density matrix…

High Energy Physics - Theory · Physics 2025-08-29 Wu-zhong Guo

The Sutherland approximation to the van der Waals forces is applied to the derivation of a self-consistent Vlasov-type field in a liquid filling a half space, bordering vacuum. The ensuing Vlasov equation is then derived, and solved to…

Soft Condensed Matter · Physics 2015-09-02 V. Molinari , B. D. Ganapol , D. Mostacci

In this work we show that the presence of a vector field on cosmological scales could explain the present phase of accelerated expansion of the universe. The proposed theory contains no dimensional parameters nor potential terms and does…

Astrophysics · Physics 2008-12-18 Jose Beltran Jimenez , Antonio L. Maroto

Implicit fields have recently shown increasing success in representing and learning 3D shapes accurately. Signed distance fields and occupancy fields are decades old and still the preferred representations, both with well-studied…

Computer Vision and Pattern Recognition · Computer Science 2023-04-10 Edoardo Mello Rella , Ajad Chhatkuli , Ender Konukoglu , Luc Van Gool