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相关论文: Nonholonomic Ricci Flows: Exact Solutions and Grav…

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We develop an approach to the theory nonholonomic relativistic stochastic processes on curved spaces. The Ito and Stratonovich calculus are formulated for spaces with conventional horizontal (holonomic) and vertical (nonholonomic) splitting…

数学物理 · 物理学 2012-03-27 Sergiu I. Vacaru

We discuss from a geometric point of view the connection between the renormalization group flow for non--linear sigma models and the Ricci flow. This offers new perspectives in providing a geometrical landscape for 2D quantum field…

高能物理 - 理论 · 物理学 2010-01-21 Mauro Carfora

We present several new space-periodic solutions of the static vacuum Einstein equations in higher dimensions, both with and without black holes, having Kasner asymptotics. These latter solutions are referred to as gravitational solitons.…

微分几何 · 数学 2022-04-25 Marcus Khuri , Martin Reiris , Gilbert Weinstein , Sumio Yamada

For any flag manifold $M=G/K$ of a compact simple Lie group $G$ we describe non-collapsing ancient invariant solutions of the homogeneous unnormalized Ricci flow. Such solutions emerge from an invariant Einstein metric on $M$, and by…

微分几何 · 数学 2021-08-03 Stavros Anastassiou , Ioannis Chrysikos

By applying the method of moving frames modelling one and two dimensional local anisotropies we construct new solutions of Einstein equations on pseudo-Riemannian spacetimes. The first class of solutions describes non-trivial deformations…

广义相对论与量子宇宙学 · 物理学 2016-08-31 Sergiu I. Vacaru

There is a common description of different intrinsic geometric flows in two dimensions using Toda field equations associated to continual Lie algebras that incorporate the deformation variable t into their system. The Ricci flow admits zero…

高能物理 - 理论 · 物理学 2009-11-11 I. Bakas

We consider anisotropic fluids with directional pressures $p_i = w_i \rho$ ($\rho$ is the density, $w_i = $const, $i = 1,2,3$) as sources of gravity in stationary cylindrically symmetric space-times. We describe a general way of obtaining…

广义相对论与量子宇宙学 · 物理学 2019-06-19 S. V. Bolokhov , K. A. Bronnikov , M. V. Skvortsova

This book gives an introduction to fundamental aspects of generalized Riemannian, complex, and K\"ahler geometry. This leads to an extension of the classical Einstein-Hilbert action, which yields natural extensions of Einstein and…

微分几何 · 数学 2020-08-31 Mario Garcia-Fernandez , Jeffrey Streets

The elliptic Einstein-DeTurck equation may be used to numerically find Einstein metrics on Riemannian manifolds. Static Lorentzian Einstein metrics are considered by analytically continuing to Euclidean time. Ricci-DeTurck flow is a…

高能物理 - 理论 · 物理学 2015-05-27 Pau Figueras , James Lucietti , Toby Wiseman

We analyse second order (in Riemann curvature) geometric flows (un-normalised) on locally homogeneous three manifolds and look for specific features through the solutions (analytic whereever possible, otherwise numerical) of the evolution…

微分几何 · 数学 2015-04-13 Sanjit Das , Kartik Prabhu , Sayan Kar

We classify solutions to Einstein's equations in AdS with Ricci-flat boundary metric and with covariantly constant boundary stress tensor, which in general is not diagonalizable, i.e. it does not admit a reference frame. New solutions are…

广义相对论与量子宇宙学 · 物理学 2017-01-30 Paolo Glorioso

A cosmological model describing the evolution of $n$ Einstein spaces $(n>1)$ with $m$-component perfect-fluid matter is considered. When all spaces are Ricci-flat and for any $\alpha$-th component the pressures in all spaces are…

广义相对论与量子宇宙学 · 物理学 2011-04-20 V. D. Ivashchuk , V. N. Melnikov

We present a new generating algorithm to construct exact non static solutions of the Einstein field equations with two-dimensional inhomogeneity. Infinite dimensional families of $G_1$ inhomogeneous solutions with a self interacting scalar…

广义相对论与量子宇宙学 · 物理学 2016-08-15 A. Feinstein , J. Ibáñez , Ruth Lazkoz

We summarize some our recent results on encoding exact solutions of field equations in Einstein and modified gravity theories into solitonic hierarchies derived for nonholonomic curve flows with associated bi-Hamilton structure. We argue…

广义相对论与量子宇宙学 · 物理学 2015-05-20 Sergiu I. Vacaru

This paper establishes a unified framework integrating geometric flows with deep learning through three fundamental innovations. First, we propose a thermodynamically coupled Ricci flow that dynamically adapts parameter space geometry to…

机器学习 · 计算机科学 2025-03-26 Ming Lei , Christophe Baehr

We formulate a statistical analogy of regular Lagrange mechanics and Finsler geometry derived from Grisha Perelman's functionals generalized for nonholonomic Ricci flows. There are elaborated explicit constructions when nonholonomically…

微分几何 · 数学 2015-06-26 Sergiu I. Vacaru

The geometric flow theory and its applications turned into one of the most intensively developing branches of modern geometry. Here, a brief introduction to Finslerian Ricci flow and their self-similar solutions known as Ricci solitons are…

微分几何 · 数学 2018-07-12 Behroz Bidabad , Mohammad Yar Ahmadi

In stark contrast to lower dimensions, we produce a plethora of ancient and immortal Ricci flows in real dimension $4$ with Einstein orbifolds as tangent flows at infinity. For instance, for any $k\in\mathbb{N}_0$, we obtain continuous…

微分几何 · 数学 2025-01-23 Alix Deruelle , Tristan Ozuch

Regarding Ricci flow as a dynamical system, we derive sufficient conditions for noncompact stationary (Ricci-flat) solutions to possess infinite-dimensional unstable manifolds, and provide examples satisfying those criteria that have…

微分几何 · 数学 2025-03-18 Sigurd B. Angenent , Dan Knopf

The Ricci flow is a heat equation for metrics, which has recently been used to study the topology of closed three manifolds. In this paper we apply Ricci flow techniques to general relativity. We view a three dimensional asymptotically flat…

广义相对论与量子宇宙学 · 物理学 2008-11-26 Joseph Samuel , Sutirtha Roy Chowdhury