A locally-built, LLM-digested index of recent arXiv papers in quant finance, geometry/topology, and statistical ML — keyword search served straight from SQLite on this machine.
In this article, we study an almost contact metric structure on a G2-manifold constructed by Arikan, Cho and Salur in via the classification of almost contact metric structures given by Chinea and Gonzalez. In particular, we characterize when this almost contact metric structure is cosymplectic and narrow down the p…
We discuss general notions of metrics and of Finsler structures which we call weak metrics and weak Finsler structures. Any convex domain carries a canonical weak Finsler structure, which we call its tautological weak Finsler structure. We compute distances in the tautological weak Finsler structure of a domain and we …
We study almost contact metric structures induced by 2-fold vector cross products on manifolds with G2 structures. We get some results on possible classes of almost contact metric structures. Finally we give examples.
The study of harmonicity for almost contact metric structures was initiated by Vergara-Díaz and Wood and continued by González-Dávila and the present author. By using the intrinsic torsion and some restriction on the type of almost contact metric structure, González-Dávila and the present author have characterised harm…
Characterizes invariant contact metric structures on tangent sphere bundles of compact symmetric spaces.
problem Identifying invariant contact metric structures on tangent sphere bundles of compact symmetric spaces.
method Characterization through invariant Riemannian metrics and Killing vector fields.
result A family of invariant contact metric structures is obtained on tangent sphere bundles of compact symmetric spaces with rank greater than or equal to two.
We consider a 3-dimensional differentiable manifold with two circulant structures -- a Riemannian metric and an additional structure, whose third power is the identity. The structure is compatible with the metric such that an isometry is induced in any tangent space of the manifold. Further, we consider an associated…
This article classifies closed G2-structures such that the induced metric is conformally flat. It is shown that any closed G2-structure with conformally flat metric is locally equivalent to one of three explicit examples. In particular, it follows from the classification that any closed G2-structure inducing a metric t…
We introduce the notion of contact pair structure and the corresponding associated metrics, in the same spirit of the geometry of almost contact structures. We prove that, with respect to these metrics, the integral curves of the Reeb vector fields are geodesics and that the leaves of the Reeb action are totally geodes…
In this paper we deal with two classes of mixed metric 3-structures, namely the mixed 3-Sasakian structures and the mixed metric 3-contact structures. Firstly we study some properties of the curvature of mixed 3-Sasakian structures, proving that any manifold endowed with such a structure is Einstein. Then we prove the …
Starting from g-natural pseudo-Riemannian metrics of suitable signature on the unit tangent sphere bundle T1M of a Riemannian manifold (M,⟨,⟩), we construct a family of paracontact metric structures. We prove that this class of paracontact metric structures is invariant under D-homothetic…
It is introduced a differentiable manifold with almost contact 3-structure which consists of an almost contact metric structure and two almost contact B-metric structures. The product of this manifold and a real line is an almost hypercomplex manifold with Hermitian-Norden metrics. It is proven that the introduced mani…
Integrable hypercomplex structures with Hermitian and Norden metrics on Lie groups of dimension 4 are considered. The corresponding five types of invariant hypercomplex structures with hyper-Hermitian metric, studied by M.L. Barberis, are constructed here. The different cases regarding the signature of the basic pseudo…
We prove that any contact metric (κ,μ)-space (M,ξ,φ,η,g) admits a canonical paracontact metric structure which is compatible with the contact form η. We study such canonical paracontact structure, proving that it verifies a nullity condition and induces on the underlying contact manifold (M,η) a sequence of com…
Study of a metric on cotangent bundle spaces of Kähler quotients.
problem Construct and analyze a metric on the total space of cotangent bundles to Kähler quotients.
method Use hyperkähler reduction to construct a hyperkähler metric, prove its coincidence with the Feix-Kaledin metric, and investigate its completeness.
result The metric completion of the space Y is a stratified hyperkähler space with an algebraic structure.
Construct quaternionic-Kähler metrics from special Kähler manifolds with specific BPS structure variations.
problem Construct quaternionic-Kähler metrics from special Kähler manifolds with mutually local variations of BPS structures.
method Construct quaternionic-Kähler metrics from a conical special Kähler manifold with a certain type of mutually-local variation of BPS structures. Provide global and local explicit formulas for the quaternionic-Kähler metric.
result Construct quaternionic-Kähler metrics that are positive-definite and deform the 1-loop corrected Ferrara-Sabharval metric.
In this paper, we consider half-flat SU(3)-structures and the subclasses of coupled and double structures. In the general case we show that the intrinsic torsion form w1− is constant in each of the two subclasses. We then consider the problem of finding half-flat structures inducing Einstein metrics on homogeneou…
Along the Ricci flow, we study the polyhomogeneity of complete Riemannian metrics endowed with "a Lie structure fibred at infinity", that is, a class of Lie structures at infinity that induce in a precise way a fibre bundle structure on a certain compactification by a manifold with corners. When the compactification is…
On a manifold with an almost contact metric structure (φ,ξ,η,g,X,D) the notions of the interior and the N-prolonged connections are introduced. Using the N-prolonged connection, a new almost contact metric structure is defined on the distribution D. The properties of this structure are studied.
We introduce a new notion of a homogeneous pair for a pseudo-Riemannian metric g and a positive function f on a manifold M admitting a free R>0-action. There are many examples admitting this structure. For example, (a) a class of pseudo-Hessian manifolds admitting a free R>0-action and…