Results 41 to 50 of about 1,532 (136)
Ricci Nilsoliton Black Holes [PDF]
, 2008 We follow a constructive approach and find higher-dimensional black holes with Ricci nilsoliton horizons. The spacetimes are solutions to Einstein's equation with a negative cosmological constant and generalises therefore, anti-de Sitter black hole ...
Aebischer +35 more
core +5 more sources
Formality and the Lefschetz property in symplectic and cosymplectic geometry
, 2015 We review topological properties of K\"ahler and symplectic manifolds, and of their odd-dimensional counterparts, coK\"ahler and cosymplectic manifolds. We focus on formality, Lefschetz property and parity of Betti numbers, also distinguishing the simply-
Bazzoni, Giovanni +2 more
core +4 more sources
The Classification of Flat Solvmanifolds [PDF]
Transactions of the American Mathematical Society, 1978 This paper contains a complete algebraic characterization of the fundamental groups of flat solvmanifolds. This characterization is in terms of finite integral representations of free abelian groups and the associated cohomology. A classification of compact flat solvmanifolds follows, and a list of all compact flat solvmanifolds of dimensions 3, 4, and
openaire +2 more sources
Topological T-Duality for Twisted Tori [PDF]
, 2020 We apply the $C^*$-algebraic formalism of topological T-duality due to Mathai and Rosenberg to a broad class of topological spaces that include the torus bundles appearing in string theory compactifications with duality twists, such as nilmanifolds, as ...
P. Aschieri, R. Szabo
semanticscholar +1 more source
Formality and hard Lefschetz property of aspherical manifolds [PDF]
, 2012 For a Lie group $G=\R^{n}\ltimes_{\phi}\R^{m}$ with the semi-simple action $\phi:\R^{n}\to {\rm Aut}(\R^{m})$, we show that if $\Gamma$ is a finite extension of a lattice of $G$ then $K(\Gamma, 1)$ is formal.
Kasuya, Hisashi
core +3 more sources
Chern‐Simons forms of pseudo‐Riemannian homogeneity on the oscillator group
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 47, Page 3007-3014, 2003., 2003 We consider forms of Chern‐Simons type associated to homogeneous pseudo‐Riemannian structures. The corresponding secondary classes are a measure of the lack of a homogeneous pseudo‐Riemannian space to be locally symmetric. In the present paper, we compute these forms for the oscillator group and the corresponding secondary classes of the compact ...
P. M. Gadea, J. A. Oubiña
wiley +1 more source
Symplectic harmonicity and generalized coeffective cohomologies [PDF]
, 2018 Relations between the symplectically harmonic cohomology and the coeffective cohomology of a symplectic manifold are obtained. This is achieved through a generalization of the latter, which in addition allows us to provide a coeffective version of the ...
Ugarte, Luis, Villacampa, Raquel
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Cohomologically Kähler manifolds with no Kähler metrics
International Journal of Mathematics and Mathematical Sciences, Volume 2003, Issue 52, Page 3315-3325, 2003., 2003 We show some examples of compact symplectic solvmanifolds, of dimension greater than four, which are cohomologically Kähler and do not admit Kähler metric since their fundamental groups cannot be the fundamental group of any compact Kähler manifold. Some of the examples that we study were considered by Benson and Gordon (1990).
Marisa Fernández +2 more
wiley +1 more source
Distinguished $$G_2$$-Structures on Solvmanifolds [PDF]
, 2020 Among closed G2-structures there are two very distinguished classes: Laplacian solitons and Extremally Ricci-pinched G2-structures. We study the existence problem and explore possible interplays between these concepts in the context of left-invariant G2-structures on solvable Lie groups.
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Examples of Compact Lefschetz Solvmanifolds [PDF]
Tokyo Journal of Mathematics, 2002 A symplectic manifold \((M^{2m},\omega)\) is called a Lefschetz manifold if the mapping \(\wedge\omega^{m-1}: H^1_{DR}\to H^{2m-1}_{DR}\) on \(M\) is an isomorphism. By a solvmanifold is meant a homogeneous space \(G/\Gamma\) where \(G\) is a simply connected solvable Lie group and \(\Gamma\) is a lattice.
openaire +2 more sources