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Related papers: Ricci flows, wormholes and critical phenomena

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In this article we examine the formation of cylindrical neckpinch singularities in Ricci flow in compact manifolds. Rigorous examples of neckpinch sigularity for rotationally symmetric initial data were first constructed by Angenent and…

Differential Geometry · Mathematics 2023-11-22 Hamidreza Mahmoudian

We investigate contributions of spacetime wormholes, describing baby universe emission and absorption, to calculations of entropies and correlation functions, for example those based on the replica method. We find that the rules of the…

High Energy Physics - Theory · Physics 2020-10-28 Steven B. Giddings , Gustavo J. Turiaci

The topology-changing transition between black strings and black holes localized in a Kaluza-Klein circle is investigated in an expansion in the inverse of the number of dimensions D. Performing a new kind of large-D scaling reduces the…

High Energy Physics - Theory · Physics 2022-03-07 Roberto Emparan , Ryotaku Suzuki

Exact solutions of traversable wormholes are found under the assumption of spherical symmetry and the existence of a {\it non-static} conformal symmetry, which presents a more systematic approach in searching for exact wormhole solutions.…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Christian G. Boehmer , Tiberiu Harko , Francisco S. N. Lobo

In this work we construct and analyze exact solutions describing Ricci flows and nonholonomic deformations of four dimensional (4D) Taub-NUT spacetimes. It is outlined a new geometric techniques of constructing Ricci flow solutions. Some…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Sergiu I. Vacaru , Mihai Visinescu

This paper investigates the question of stability for a class of Ricci flows which start at possibly non-smooth metric spaces. We show that if the initial metric space is Reifenberg and locally bi-Lipschitz to Euclidean space, then two…

Differential Geometry · Mathematics 2025-03-18 Alix Deruelle , Felix Schulze , Miles Simon

We investigate the properties of the combinatorial Ricci flow for surfaces, both forward and backward -- existence, uniqueness and singularities formation. We show that the positive results that exist for the smooth Ricci flow also hold for…

Differential Geometry · Mathematics 2011-06-09 Emil Saucan

In this paper, we study the evolution of $L^2$ one forms under Ricci flow with bounded curvature on a non-compact Rimennian manifold. We show on such a manifold that the $L^2$ norm of a smooth one form with compact support is non-increasing…

Differential Geometry · Mathematics 2007-05-23 Li Ma , Yang Yang

This survey reviews some facts about nonnegativity conditions on the curvature tensor of a Riemannian manifold which are preserved by the action of the Ricci flow. The text focuses on two main points. First we describe the known examples of…

Differential Geometry · Mathematics 2014-11-21 Thomas Richard

Growth of wormholes in porous media can lead to self-organization of flow networks with an overwhelming geometric complexity. Despite decades of study, the mechanism by which a dominant wormhole develops its path during growth remains…

Geophysics · Physics 2019-05-17 Y. Yang , S. S. Hakim , S. Bruns , K. Uesugi , K. N. Dalby , S. L. S. Stipp , H. O. Sørensen

The present paper is devoted to the study a global aspect of the geometry of harmonic mappings and, in particular, infinitesimal harmonic transformations, and represents the application of our results to the theory of Ricci solutions and…

Differential Geometry · Mathematics 2019-06-19 Sergey Stepanov , Irina Aleksandrova , Irina Tsyganok

In this work, we consider the possibility of expanding wormholes in higher-dimensions, which is an important ingredient of modern theories of fundamental physics. An important motivation is that non-trivial topological objects such as…

General Relativity and Quantum Cosmology · Physics 2014-07-30 Mahdi Kord Zangeneh , Francisco S. N. Lobo , Nematollah Riazi

Neural networks with PDEs embedded in their loss functions (physics-informed neural networks) are employed as a function approximators to find solutions to the Ricci flow (a curvature based evolution) of Riemannian metrics. A general method…

General Relativity and Quantum Cosmology · Physics 2022-12-13 Aarjav Jain , Challenger Mishra , Pietro Liò

We present here analytical solutions of General Relativity that describe evolving wormholes with a non-constant redshift function. We show that the matter that threads these wormholes is not necessarily exotic. Finally, we investigate some…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Luis A. Anchordoqui , Diego F. Torres , Marta L. Trobo , Santiago E. Perez Bergliaffa

In this paper we study the possibility of sustaining an evolving wormhole via exotic matter made out of phantom energy. We show that this exotic source can support the existence of evolving wormhole spacetimes. Explicitly, a family of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Mauricio Cataldo , Pedro Labrana , Sergio del Campo , Juan Crisostomo , Patricio Salgado

In this paper we study a boundary value problem for the Ricci flow in the two dimensional ball endowed with a rotationally symmetric metric. We show short and long time existence results. We construct families of metrics for which the flow…

Differential Geometry · Mathematics 2007-05-23 Jean Cortissoz

We survey several problems concerning Riemannian manifolds with positive curvature of one form or another. We describe the PIC1 notion of positive curvature and argue that it is often the sharp notion of positive curvature to consider.…

Differential Geometry · Mathematics 2023-09-04 Peter M. Topping

We consider four extended Ricci flow systems---that is, Ricci flow coupled with other geometric flows---and prove dynamical stability of certain classes of stationary solutions of these flows. The systems include Ricci flow coupled with…

Differential Geometry · Mathematics 2015-06-22 Michael Bradford Williams

Lack of a consistent metric for generating rotating wormholes motivates us to present a new one endowed with interesting physical and geometrical properties. When combined with the generalized method of superposition of fields, which…

General Relativity and Quantum Cosmology · Physics 2016-01-07 Mustapha Azreg-Aïnou

We develop different synthetic notions of Ricci flow in the setting of time-dependent metric measure spaces based on ideas from optimal transport. They are formulated in terms of dynamic convexity and local concavity of the entropy along…

Differential Geometry · Mathematics 2025-01-14 Matthias Erbar , Zhenhao Li , Timo Schultz