Results 1 to 10 of about 10,035 (101)

Navigation problem and conformal vector fields [PDF]

AUT Journal of Mathematics and Computing, 2021
The navigation technique is very effective to obtain or classify a Finsler metric from a given a Finsler metric (especially a Riemannian metric) under an action of a vector field on a differential manifold.
Qiaoling Xia
doaj   +1 more source

On 4-dimensional Einsteinian manifolds with parallel null distribution [PDF]

ریاضی و جامعه, 2023
In this paper, we investigate the Einsteinian manifolds with parallel null distribution. For this purpose, we first obtain the equations, which are known as Einstein's equations, that lead to finding the mentioned manifolds and then, we reduce Einstein's
Mehdi Jafari
doaj   +1 more source

Generalized Sums over Histories for Quantum Gravity I. Smooth Conifolds [PDF]

, 1993
This paper proposes to generalize the histories included in Euclidean functional integrals from manifolds to a more general set of compact topological spaces.
Amsterdamski, Anderson, Besse, Coleman, DeWitt, Donald M. Witt, Freedman, Gao, Gell-Mann, Geroch, Gibbons, Giddings, Glimm, Halliwell, Halliwell, Halliwell, Hartle, Hartle, Hartle, Hawking, Hawking, Hawking, Hirsch, Kirby, Kobayashi, Kristin Schleich, Nash, Page, Polchinski, Reed, Rourke, Schleich, Schleich, Spanier, Thurston, Uhlenbeck, Witt, Wright   +37 more
core   +3 more sources

Hyperbolic Gradient-Bourgoignon Flow

پژوهش‌های ریاضی, 2022
Introduction ‎Ricci solitons as a generalization of Einstein manifolds introduced by Hamilton in mid 1980s‎. ‎In the last two decades‎, ‎a lot of researchers have been done on Ricci solitons‎.
Hamed Faraji, Shahroud Azami, Ghodratallah Fasihi-Ramandi   +2 more
doaj  

Exotic Spaces in Quantum Gravity I: Euclidean Quantum Gravity in Seven Dimensions [PDF]

, 1999
It is well known that in four or more dimensions, there exist exotic manifolds; manifolds that are homeomorphic but not diffeomorphic to each other. More precisely, exotic manifolds are the same topological manifold but have inequivalent differentiable ...
Aloff S, Carlip S, Donald Witt, Freedman M, Freund P, Gibbons G, Gibbons G W, Gromoll D, Hawking S W, Hawking S W, Hirsch M W, Kirby R, Kreck M, Kreck M, Kristin Schleich, Milnor J, Moise E, Press W, Wallach N, Wang M   +19 more
core   +4 more sources

Closed manifolds admitting metrics with the same geodesics

, 2004
The goal of this survey is to give a list of resent results about topology of manifolds admitting different metrics with the same geodesics. We emphasize the role of the theory of integrable systems in obtaining these results.Comment: Submitted to ...
Matveev, Vladimir S.
core   +1 more source

On geodesics in low regularity

, 2018
We consider geodesics in both Riemannian and Lorentzian manifolds with metrics of low regularity. We discuss existence of extremal curves for continuous metrics and present several old and new examples that highlight their subtle interrelation with ...
Steinbauer, Roland, Sämann, Clemens
core   +1 more source

Surfaces with boundary: their uniformizations, determinants of Laplacians, and isospectrality

, 2006
Let \Sigma be a compact surface of type (g, n), n > 0, obtained by removing n disjoint disks from a closed surface of genus g. Assuming \chi(\Sigma)0; while Osgood, Phillips, and Sarnak \cite{OPS3} showed the properness when g=0.Comment: Further Revised.
Kim, Young-Heon
core   +4 more sources

Isoparametric functions and exotic spheres [PDF]

, 2012
The first part of the paper is to improve the fundamental theory of isoparametric functions on general Riemannian manifolds. Next we focus our attention on exotic spheres, especially on "exotic" 4-spheres (if exist) and the Gromoll-Meyer sphere.
Banghe Li, Dedicated Professor, Jianquan Ge, Zizhou Tang   +3 more
core  

K\"ahler metrics via Lorentzian Geometry in dimension four

, 2019
Given a semi-Riemannian $4$-manifold $(M,g)$ with two distinguished vector fields satisfying properties determined by their shear, twist and various Lie bracket relations, a family of K\"ahler metrics $g_K$ is constructed, defined on an open set in $M ...
Aazami, Amir Babak, Maschler, Gideon
core   +1 more source