Results 131 to 140 of about 12,500,002 (282)
Extensions of Steiner Triple Systems
ABSTRACT In this article, we study extensions of Steiner triple systems by means of the associated Steiner loops. We recognize that the set of Veblen points of a Steiner triple system corresponds to the center of the Steiner loop. We investigate extensions of Steiner loops, focusing in particular on the case of Schreier extensions, which provide a ...
Giovanni Falcone+2 more
wiley +1 more source
One-dimensional super Calabi-Yau manifolds and their mirrors
We apply a definition of generalised super Calabi-Yau variety (SCY) to supermanifolds of complex dimension one. One of our results is that there are two SCY’s having reduced manifold equal to ℙ 1 $$ {\mathrm{\mathbb{P}}}^1 $$ , namely the projective ...
S. Noja+4 more
doaj +1 more source
Twisted conjugacy in soluble arithmetic groups
Abstract Reidemeister numbers of group automorphisms encode the number of twisted conjugacy classes of groups and might yield information about self‐maps of spaces related to the given objects. Here, we address a question posed by Gonçalves and Wong in the mid‐2000s: we construct an infinite series of compact connected solvmanifolds (that are not ...
Paula M. Lins de Araujo+1 more
wiley +1 more source
The second bounded cohomology of a group with infinitely many ends [PDF]
We study the second bounded cohomology of an amalgamated free product of groups, and an HNN extension of a group. As an application, we have a group with infinitely many ends has infinite dimensional second bounded cohomology.
arxiv
Continuous Group Cohomology and Ext-Groups
We prove that the continuous group cohomology groups of a locally profinite group $ G $ with coefficients in a smooth $ k $-representation $ $ of $ G $ are isomorphic to the $ \mathrm{Ext}$-groups $ \mathrm{Ext}^i_G(\mathbb{1}, ) $ computed in the category of smooth $ k $-representations of $ G $.
openaire +4 more sources
A Spectral Sequence Connecting Continuous With Locally Continuous Group Cohomology [PDF]
We present a spectral sequence connecting the continuous and 'locally continuous' group cohomologies for topological groups. As an application it is shown that for contractible topological groups these cohomology concepts coincide. Similar results for k-groups and smooth cochains on Lie groups are also obtained.
arxiv
On the Integral Cohomology of Bianchi Groups [PDF]
Extensive and systematic machine computations are carried out to investigate the integral cohomology of the Euclidean Bianchi groups and their congruence subgroups. The collected data give insight on several aspects, including the asymptotic behaviour of the torsion in the first homology.
openaire +4 more sources
Hodge numbers and invariant complex structures of compact nilmanifolds
In this paper, we consider several invariant complex structures on a compact real nilmanifold, and we study relations between invariant complex structures and Hodge numbers.
Yamada Takumi
doaj +1 more source
Duality of Hodge numbers of compact complex nilmanifolds
A compact K¨ahlerian manifoldM of dimension n satisfies hp,q(M) = hq,p(M) for each p, q.However, a compact complex manifold does not satisfy the equations in general. In this paper, we consider duality of Hodge numbers of compact complex nilmanifolds.
Yamada Takumi
doaj +1 more source
Symmetric cohomology of groups as a Mackey functor [PDF]
Symmetric cohomology of groups, defined by M. Staic in [2], is similar to the way one defines the cyclic cohomology for algebras. We show that there is a well-defined restriction, conjugation and transfer map in symmetric cohomology, which form a Mackey functor under a restriction. Some new properties for the symmetric cohomology group using normalized
arxiv