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Related papers: The Einstein Relation on Metric Measure Spaces

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We review the experimental evidence for Einstein's special and general relativity. A variety of high precision null experiments verify the weak equivalence principle and local Lorentz invariance, while gravitational redshift and other clock…

General Relativity and Quantum Cosmology · Physics 2011-07-19 Clifford M. Will

We present a local classification of conformally equivalent but oppositely oriented 4-dimensional Kaehler metrics which are toric with respect to a common 2-torus action. In the generic case, these "ambitoric" structures have an intriguing…

Differential Geometry · Mathematics 2016-11-28 Vestislav Apostolov , David M. J. Calderbank , Paul Gauduchon

Assuming the minimal time to send a bit of information in the Einstein clock synchronization of the two clocks located at different positions, we introduce the extended metric to the information space. This modification of relativity…

General Relativity and Quantum Cosmology · Physics 2018-05-01 Akio Hosoya , Shunsuke Fujii

Our conventional system of physical units is based on local or microscopic {\it dimensional} quantities which are {\it defined}, for convenience or otherwise aesthetic reasons, to be spacetime-independent. A more general choice of units may…

General Physics · Physics 2013-08-06 Meir Shimon

We study various measure theories using the classical approach and then compute the Hausdorff dimension of some simple objects and self-similar fractals. We then develop a nonstandard approach to these measure theories and examine the…

Logic · Mathematics 2018-12-06 Mee Seong Im

This document offers a concise introduction to the mathematical theory and practical application of the Hausdorff Measure and Dimension. The primary objective is to clarify and rigorously detail the two most common methods used for…

History and Overview · Mathematics 2025-11-20 Umberto Michelucci

It is well known that any 4-dimensional hyperkahler metric with two commuting Killing fields may be obtained explicitly, via the Gibbons-Hawking Ansatz, from a harmonic function invariant under a Killing field on R^3. In this paper, we find…

Differential Geometry · Mathematics 2007-05-23 David M. J. Calderbank , Henrik Pedersen

We study physical consequences of the Einstein equivalence principle (EEP) for a Hubble observer in FLRW universe. We introduce the local inertial coordinates with the help of a special conformal transformation. The local inertial metric is…

General Relativity and Quantum Cosmology · Physics 2014-02-19 Sergei M. Kopeikin

Two pseudo-Riemannian metrics are called projectively equivalent if their unparametrized geodesics coincide. The degree of mobility of a metric is the dimension of the space of metrics that are projectively equivalent to it. We give a…

Differential Geometry · Mathematics 2017-11-28 Vladimir S. Matveev , Stefan Rosemann

Let E be a metric space. We introduce a notion of connectedness index of E, which is the Hausdor? dimension of the union of non-trivial connected components of E. We show that the connectedness index of a fractal cube E is strictly less…

General Topology · Mathematics 2020-10-27 Liangyi Huang , Hui Rao

We consider inverse problems for the Einstein equation with a time-depending metric on a 4-dimensional globally hyperbolic Lorentzian manifold $(M,g)$. We formulate the concept of active measurements for relativistic models. We do this by…

Analysis of PDEs · Mathematics 2013-05-30 Yaroslav Kurylev , Matti Lassas , Gunther Uhlmann

We analyse in a systematic way the (non-)compact four dimensional Einstein-Weyl spaces equipped with a Bianchi metric. We show that Einstein-Weyl structures with a Class A Bianchi metric have a conformal scalar curvature of constant sign on…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Guy Bonneau

The intimate relations between Einstein's equation, conformal geometry, geometric asymptotics, and the idea of an isolated system in general relativity have been pointed out by Penrose many years ago. A detailed analysis of the interplay of…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Helmut Friedrich

We give an overview of progress on homogeneous Einstein metrics on large classes of homogeneous manifolds, such as generalized flag manifolds and Stiefel manifolds. The main difference between these two classes of homogeneous spaces is that…

Differential Geometry · Mathematics 2016-05-20 Andreas Arvanitoyeorgos

The Einstein-Schrodinger theory is modified by adding a cosmological constant contribution caused by zero-point fluctuations. This cosmological constant which multiplies the symmetric metric is assumed to be nearly cancelled by…

General Relativity and Quantum Cosmology · Physics 2007-05-23 J. A. Shifflett

In this short note, we show that, in any given metric space, every Lipschitz open-map image of every subset of a given metric space whose boundary is Hausdorff-null is Hausdorff-measurable with respect to the same dimension. The main…

General Mathematics · Mathematics 2020-06-08 Yu-Lin Chou

Einstein, in his "Zur Elektrodynamik bewegter Korper", gave a physical (operational) meaning to "time" of a remote event in describing "motion" by introducing the concept of "synchronous stationary clocks located at different places". But…

History and Philosophy of Physics · Physics 2009-11-11 S. D. Agashe

The classification of homogeneous compact Einstein manifolds in dimension six is an open problem. We consider the remaining open case, namely left-invariant Einstein metrics $g$ on $G = \mathrm{SU}(2) \times \mathrm{SU}(2) = S^3 \times…

Differential Geometry · Mathematics 2018-07-10 Florin Belgun , Vicente Cortés , Alexander S. Haupt , David Lindemann

In the present paper we investigate the properties of the Hausdorff mapping $\mathcal{H}$, which takes each compact metric space to the space of its nonempty closed subspaces. It is shown that this mapping is nonexpanding (Lipschitz mapping…

Metric Geometry · Mathematics 2017-10-26 Ivan A. Mikhaylov

We consider the fractal characteristic of the quantum mechanical paths and we obtain for any universal class of fractons labeled by the Hausdorff dimension defined within the interval 1$ $$ < $$ $$h$$ $$ <$$ $$ 2$, a fractal distribution…

Statistical Mechanics · Physics 2009-11-07 Wellington da Cruz