Results 21 to 30 of about 317 (142)
Purely coclosed G2‐structures on nilmanifolds
Mathematische Nachrichten, Volume 296, Issue 6, Page 2236-2257, June 2023., 2023 Abstract We classify seven‐dimensional nilpotent Lie groups, decomposable or of nilpotency step at most 4, endowed with left‐invariant purely coclosed G2‐structures. This is done by going through the list of all seven‐dimensional nilpotent Lie algebras given by Gong, providing an example of a left‐invariant 3‐form φ which is a pure coclosed G2 ...
Giovanni Bazzoni +2 more
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Multiple recurrence and convergence without commutativity
Journal of the London Mathematical Society, Volume 107, Issue 5, Page 1635-1659, May 2023., 2023 Abstract We establish multiple recurrence and convergence results for pairs of zero entropy measure preserving transformations that do not satisfy any commutativity assumptions. Our results cover the case where the iterates of the two transformations are n$n$ and nk$n^k$, respectively, where k⩾2$k\geqslant 2$, and the case k=1$k=1$ remains an open ...
Nikos Frantzikinakis, Bernard Host
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Mathematika, Volume 69, Issue 1, Page 250-285, January 2023., 2023 Abstract We introduce a class of multiplicative functions in which each function satisfies some statistic conditions, and then prove that the above functions are not correlated with finite degree polynomial nilsequences. Besides, we give two applications of this result. One is that the twisting of coefficients of automorphic L‐function on GLm(m⩾2)$GL_m
Xiaoguang He, Mengdi Wang
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Pluriclosed and Strominger Kähler–like metrics compatible with abelian complex structures
Bulletin of the London Mathematical Society, Volume 54, Issue 5, Page 1862-1872, October 2022., 2022 Abstract We show that the existence of a left‐invariant pluriclosed Hermitian metric on a unimodular Lie group with a left‐invariant abelian complex structure forces the group to be 2‐step nilpotent. Moreover, we prove that the pluriclosed flow starting from a left‐invariant Hermitian metric on a 2‐step nilpotent Lie group preserves the Strominger ...
Anna Fino +2 more
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A compact non‐formal closed G2 manifold with b1=1$b_1=1$
Mathematische Nachrichten, Volume 295, Issue 8, Page 1562-1590, August 2022., 2022 Abstract We construct a compact manifold with a closed G2 structure not admitting any torsion‐free G2 structure, which is non‐formal and has first Betti number b1=1$b_1=1$. We develop a method of resolution for orbifolds that arise as a quotient M/Z2$M/{{\mathbb {Z}}_2}$ with M a closed G2 manifold under the assumption that the singular locus carries a
Lucía Martín‐Merchán
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Dold sequences, periodic points, and dynamics
Bulletin of the London Mathematical Society, Volume 53, Issue 5, Page 1263-1298, October 2021., 2021 Abstract In this survey we describe how the so‐called Dold congruence arises in topology, and how it relates to periodic point counting in dynamical systems.
Jakub Byszewski +2 more
wiley +1 more source
On the structure of double complexes
Journal of the London Mathematical Society, Volume 104, Issue 2, Page 956-988, September 2021., 2021 Abstract We study consequences and applications of the folklore statement that every double complex over a field decomposes into so‐called squares and zigzags. This result makes questions about the associated cohomology groups and spectral sequences easy to understand.
Jonas Stelzig
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Fortschritte der Physik, Volume 69, Issue 7, July 2021., 2021 Abstract The history of the geometry of Double Field Theory is the history of string theorists' effort to tame higher geometric structures. In this spirit, the first part of this paper will contain a brief overview on the literature of geometry of DFT, focusing on the attempts of a global description. In [1] we proposed that the global doubled space is
Luigi Alfonsi
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Tachyonic de Sitter Solutions of 10d Type II Supergravities
Fortschritte der Physik, Volume 69, Issue 7, July 2021., 2021 Abstract Cosmological models of the early or late universe exhibit (quasi) de Sitter space‐times with different stability properties. Considering models derived from string theory, the swampland program does not provide for now a definite characterisation of this stability.
David Andriot
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Coincidence Wecken Property for Nilmanifolds [PDF]
Acta Mathematica Sinica, English Series, 2018 Let $f,g:X\to Y$ be maps from a compact infra-nilmanifold $X$ to a compact nilmanifold $Y$ with $\dim X\ge \dim Y$. In this note, we show that a certain Wecken type property holds, i.e., if the Nielsen number $N(f,g)$ vanishes then $f$ and $g$ are deformable to be coincidence free.
Gonçalves, Daciberg, Wong, Peter
openaire +3 more sources