Results 21 to 30 of about 233 (46)
Two closed orbits for non-degenerate Reeb flows
, 2020 We prove that every non-degenerate Reeb flow on a closed contact manifold $M$ admitting a strong symplectic filling $W$ with vanishing first Chern class carries at least two geometrically distinct closed orbits provided that the positive equivariant ...
Abreu, Miguel +3 more
core +2 more sources
Journal of Topology, Volume 13, Issue 3, Page 939-968, September 2020., 2020 Abstract We specify exterior generators in π∗THH(MU)=π∗(MU)⊗E(λn′∣n⩾1) and π∗THH(BP)=π∗(BP)⊗E(λn∣n⩾1), and calculate the action of the σ‐operator on these graded rings. In particular, σ(λn′)=0 and σ(λn)=0, while the actions on π∗(MU) and π∗(BP) are expressed in terms of the right units ηR in the Hopf algebroids (π∗(MU),π∗(MU∧MU)) and (π∗(BP),π∗(BP∧BP)),
John Rognes
wiley +1 more source
Open Mathematics, 2019 In this paper we define and investigate nearly Hurewicz spaces and their star version. It is shown that a nearly Hurewicz space fits between Hurewicz and almost Hurewicz spaces.
Aqsa, Khan Moiz ud Din
doaj +1 more source
Global properties of gravitational lens maps in a Lorentzian manifold setting [PDF]
, 2000 In a general-relativistic spacetime (Lorentzian manifold), gravitational lensing can be characterized by a lens map, in analogy to the lens map of the quasi-Newtonian approximation formalism.
Perlick, Volker
core +3 more sources
Remarks on strongly star-Hurewicz spaces
Filomat, 2013 A space X is strongly star-Hurewicz if for each sequence (Un : n ∈ N) of open covers of X there exists a sequence (An : n ∈ N) of finite subsets of X such that for each x ∈ X, x ∈ St(An; Un) for all but finitely many n. In this paper, we continue to investigate topological properties of strongly star-Hurewicz spaces.
openaire +2 more sources
Heegaard-Floer homology and string links
, 2006 We extend knot Floer homology to string links in D^{2} \times I and to d-based links in arbitrary three manifolds, without any hypothesis on the null-homology of the components.
Burde +8 more
core +2 more sources
, 2008 Many things in mathematics seem lamost unreasonably nice. This includes objects, counterexamples, proofs. In this preprint I discuss many examples of this phenomenon with emphasis on the ring of polynomials in a countably infinite number of variables in ...
Hazewinkel, Michiel
core +2 more sources
The Picard group in equivariant homotopy theory via stable module categories
Journal of Topology, Volume 18, Issue 2, June 2025.Abstract We develop a mechanism of “isotropy separation for compact objects” that explicitly describes an invertible G$G$‐spectrum through its collection of geometric fixed points and gluing data located in certain variants of the stable module category.
Achim Krause
wiley +1 more source
Fundamental groups of clique complexes of random graphs
Transactions of the London Mathematical Society, Volume 2, Issue 1, Page 1-32, 2015., 2015 We study fundamental groups of clique complexes associated to random Erdős–Rényi graphs Γ. We establish thresholds for a number of properties of fundamental groups of these complexes XΓ. In particular, if p=nα, then we show that gdim(π1(XΓ))=cd(π1(XΓ))=1ifα<−12,gdim(π1(XΓ))=cd(π1(XΓ))=2if−12<α<−1130,gdim(π1(XΓ))=cd(π1(XΓ))=∞if−1130<α<−13 ...
Armindo Costa +2 more
wiley +1 more source
Assouad–Nagata dimension of minor‐closed metrics
Proceedings of the London Mathematical Society, Volume 130, Issue 3, March 2025.Abstract Assouad–Nagata dimension addresses both large‐ and small‐scale behaviors of metric spaces and is a refinement of Gromov's asymptotic dimension. A metric space M$M$ is a minor‐closed metric if there exists an (edge‐)weighted graph G$G$ satisfying a fixed minor‐closed property such that the underlying space of M$M$ is the vertex‐set of G$G$, and
Chun‐Hung Liu
wiley +1 more source