Results 11 to 20 of about 735 (92)
Strongly positive curvature [PDF]
, 2014 We begin a systematic study of a curvature condition (strongly positive curvature) which lies strictly between positive curvature operator and positive sectional curvature, and stems from the work of Thorpe in the 1970s.
Bettiol, Renato G. +1 more
core +1 more source
Manifolds with 1/4-pinched flag curvature [PDF]
, 2009 We say that a nonnegatively curved manifold $(M,g)$ has quarter pinched flag curvature if for any two planes which intersect in a line the ratio of their sectional curvature is bounded above by 4.
A. Petrunin +24 more
core +6 more sources
Global surfaces of section for Reeb flows in dimension three and beyond
, 2020 We survey some recent developments in the quest for global surfaces of section for Reeb flows in dimension three using methods from Symplectic Topology.
Hryniewicz, Umberto L. +1 more
core +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 +37 more
core +3 more sources
Notes on Perelman's papers [PDF]
, 2008 These are detailed notes on Perelman's papers "The entropy formula for the Ricci flow and its geometric applications" and "Ricci flow with surgery on three-manifolds".Comment: 216 pages, minor corrections ...
Anderson +33 more
core +3 more sources
Contact structures and Beltrami fields on the torus and the sphere
, 2021 We present new explicit tight and overtwisted contact structures on the (round) 3-sphere and the (flat) 3-torus for which the ambient metric is weakly compatible.
Peralta-Salas, Daniel, Slobodeanu, Radu
core +1 more source
The topology of closed manifolds with quasi-constant sectional curvature [PDF]
, 2019 We prove that closed manifolds admitting a generic metric whose sectional curvature is locally quasi-constant are graphs of space forms. In the more general setting of QC spaces where sets of isotropic points are arbitrary, under suitable positivity ...
Funar, Louis
core +5 more sources
Mathematics, 2022 In shape analysis, the interpolation of shapes’ trajectories is often performed by means of geodesics in an appropriate Riemannian Shape Space. Over the past several decades, different metrics and shape spaces have been proposed, including Kendall shape ...
V. Varano +5 more
semanticscholar +1 more source
Topological Signals of Singularities in Ricci Flow [PDF]
, 2017 We implement methods from computational homology to obtain a topological signal of singularity formation in a selection of geometries evolved numerically by Ricci flow.
Alsing, Paul M. +6 more
core +4 more sources
Ambitoric geometry I: Einstein metrics and extremal ambikaehler structures [PDF]
, 2013 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 local geometry
V. Apostolov +2 more
semanticscholar +1 more source