English
Related papers

Related papers: Rigid motion revisited: rigid quasilocal frames

200 papers

This paper challenges some of the common assumptions underlying the mathematics used to describe the physical world. We start by reviewing many of the assumptions underlying the concepts of real, physical, rigid bodies and the translational…

Mathematical Physics · Physics 2010-05-06 Philip H. Butler , Niels G. Gresnigt , Peter F. Renaud

Several years ago the so-called quantum geometrodynamics in extended phase space was proposed. The main role in this version of quantum geometrodynamics is given to a wave function that carries information about geometry of the Universe as…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. P. Shestakova

Conventional approaches to quantum gravity regard quantum principles, such as nonlocality and superposition, as fundamental properties of nature and therefore argue that gravity must also be quantized. In contrast, this work introduces a…

General Relativity and Quantum Cosmology · Physics 2025-05-16 Filip Strubbe

A brief review of main features of the new approach named ``quantum geometrodynamics in extended phase space'' is given and its possible prospects are discussed. Gauge degrees of freedom are treated as a subsystem of the Universe which…

General Relativity and Quantum Cosmology · Physics 2007-05-23 T. P. Shestakova

In this paper we analyze the local and global boundary rigidity problem for general Riemannian manifolds with boundary $(M,g)$. We show that the boundary distance function, i.e., $d_g|_{\partial M\times\partial M}$, known near a point $p\in…

Differential Geometry · Mathematics 2021-05-13 Plamen Stefanov , Gunther Uhlmann , Andras Vasy

This paper considers a system modelling the evolution of a rigid body immersed in a bidimensional incompressible perfect fluid. In the special case of a disk-shaped rigid body, it was shown by C. Rosier and L. Rosier (2009) that the system…

Analysis of PDEs · Mathematics 2026-03-25 Xiaoguang You

The notions of "motion" and "conserved quantities", if applied to extended objects, are already quite non-trivial in Special Relativity. This contribution is meant to remind us on all the relevant mathematical structures and constructions…

Mathematical Physics · Physics 2021-04-07 Domenico Giulini

On the path towards quantum gravity, we find friction between temporal relations in quantum mechanics (QM) (where they are fixed and field-independent), and in general relativity (where they are field-dependent and dynamic). This paper aims…

General Relativity and Quantum Cosmology · Physics 2017-11-28 Henrique Gomes

We describe a theory of quantum gravity which is based on the assumption that the spacetime structure at small distances is given by a piecewise linear (PL) 4-manifold corresponding to a triangulation of a smooth 4-manifold. The fundamental…

General Relativity and Quantum Cosmology · Physics 2018-07-18 Aleksandar Mikovic , Marko Vojinovic

A rigid body $\mathcal{B}$ moves in an otherwise quiescent viscous liquid filling the whole space outside $\mathcal{B}$, under the action of a time-periodic force $\boldsymbol{\mathsf{f}}$ of period $T$ applied to a given point of…

Analysis of PDEs · Mathematics 2025-10-28 Mher Marc Karakouzian , Giovanni P. Galdi

In this work we introduce Relativistic Quantum Geometry (RQG) on a Modern Kaluza-Klein theory by studying the boundary conditions on a extended Einstein-Hilbert action for a 5D vacuum defined on a 5D (background) Riemannian manifold. We…

General Relativity and Quantum Cosmology · Physics 2019-04-19 Mauricio Bellini , José Edgar Madriz Aguilar , Mariana Montes , Pablo Alejandro Sánchez

We construct the quartic version of generalized quasi-topological gravity, which was recently constructed to cubic order in arXiv: 1703.01631. This class of theories includes Lovelock gravity and a known form of quartic quasi-topological…

High Energy Physics - Theory · Physics 2017-08-23 Jamil Ahmed , Robie A. Hennigar , Robert B. Mann , Mozhgan Mir

A method for studying the causal structure of space-time evolution systems is presented. This method, based on a generalization of the well known Riemann problem, provides intrinsic results which can be interpreted from the geometrical…

General Relativity and Quantum Cosmology · Physics 2007-05-23 C. Bona , C. Palenzuela

A generalized definition of a frame of reference in spaces with affine connections and metrics is proposed based on the set of the following differential-geometric objects: (a) a non-null (non-isotropic) vector field, (b) the orthogonal to…

General Relativity and Quantum Cosmology · Physics 2016-08-31 S. Manoff

The Cosmological Problem is considered in a five-dimensional (bulk) manifold with two time coordinates, obeying vacuum Einstein field equations. The evolution formalism is used there, in order to get a simple form of the resulting…

General Relativity and Quantum Cosmology · Physics 2019-02-27 Carles Bona , Miguel Bezares , Bartolomé Pons-Rullan , Daniele Viganò

We study skew-product dynamics for a large class of finitely-generated semi--hyperbolic semigroups of rational maps acting on the Riemann sphere, which generalizes both the theory of iteration of a single rational map of a single complex…

Dynamical Systems · Mathematics 2022-09-27 Jason Atnip , Hiroki Sumi , Mariusz Urbański

A new non-perturbative approach to quantum theory in curved spacetime and to quantum gravity, based on a generalisation of the Wigner equation, is proposed. Our definition for a Wigner equation differs from what have otherwise been…

High Energy Physics - Theory · Physics 2009-10-30 Frank Antonsen

We study mappings on sub-Riemannian manifolds which are quasi-regular with respect to the Carnot-Caratheodory distances and discuss several related notions. On H-type Carnot groups, quasiregular mappings have been introduced earlier using…

Metric Geometry · Mathematics 2016-06-21 Katrin Fassler , Anton Lukyanenko , Kirsi Peltonen

Our previous work developed a framework for treating the motion of a small body in general relativity, based on a one-parameter-family of solutions to Einstein's equation. Here we give an analysis of the coordinate freedom allowed within…

General Relativity and Quantum Cosmology · Physics 2011-07-28 Samuel E. Gralla , Robert M. Wald

We analyse a mechanical system in two-dimensional relative motion with friction. Although the system is simple, the peculiar interplay between two kinetic friction forces and gravity leads to the wide range of admissible solutions exceeding…

Physics Education · Physics 2007-05-23 Dariusz Grech , Zygmunt Mazur