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arXiv research

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.

168,742 papers · 148 categories

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25.0%50.0%75.0%100.0% · Sep 199219922001200920172026
48 results for compact structure groups

Generalizes Dolbeault cohomology computation to Levi-flat CR structures on compact Lie groups.

problem Computing Dolbeault cohomology for Levi-flat CR structures on compact Lie groups.
method Algebraic classification of left-invariant CR structures combined with Pittie's result on compact Lie groups.
result Generalization of Dolbeault cohomology computation to Levi-flat CR structures.

No exact G₂-structures on compact Lie group quotients.

problem Existence of exact G₂-structures on compact quotients of Lie groups.
method Analyzing compact quotients of seven-dimensional Lie groups by co-compact discrete subgroups.
result Compact quotients of seven-dimensional Lie groups by co-compact discrete subgroups do not admit exact G₂-structures induced by left-invariant ones.

Compact complex manifolds with specific group actions are conformally flat.

problem Compact complex manifolds with invariant conformal holomorphic structures.
method Study of manifolds with transitive and essentially acting complex semi-simple Lie groups.
result If a complex semi-simple Lie group acts transitively and essentially, the manifold is conformally flat.

Researchers compute cohomology of Lie groups using Lie algebras.

problem Computing cohomology of left-invariant elliptic and hypocomplex structures on compact Lie groups.
method Used the Leray spectral sequence connecting Lie algebras to Dolbeault cohomology of homogeneous manifolds.
result Cohomology can be computed purely algebraically.

New complex structures found on tangent bundles of Lie groups.

problem Finding integrable complex structures on tangent bundles of Lie groups.
method Inspired by Samelson's construction, a left-invariant integrable almost complex structure is defined on the tangent bundle of any compact Lie group.
result Tangent bundles of compact Lie groups admit left-invariant integrable almost complex structures.

We introduce the group-compact coarse structure on a Hausdorff topological group in the context of coarse structures on an abstract group which are compatible with the group operations. We develop asymptotic dimension theory for the group-compact coarse structure generalizing several familiar results for discrete group…

2012-01-23abs ↗pdf ↗

We study locally compact contractive local groups, that is, locally compact local groups with a contractive pseudo-automorphism. We prove that if such an object is locally connected, then it is locally isomorphic to a Lie group. We also prove a related structure theorem for locally compact contractive local groups whic…

2009-09-24abs ↗pdf ↗

We describe simply connected compact exceptional simple Lie groups in very elementary way. We first construct all simply connected compact exceptional Lie groups G concretely. Next, we find all involutive automorphisms of G, and determine the group structures of the fixed points subgroup. They correspond to the classif…

2009-02-03abs ↗pdf ↗

Classifies Spin(7) structures on compact 8-manifolds with abelian fundamental group.

problem Classifying Spin(7) structures on compact 8-manifolds.
method Obstruction theory applied to Spin(7) structures on compact 8-manifolds with abelian fundamental group.
result Compact Riemannian 8-manifolds with holonomy Spin(7) have exactly two Spin(7) structures extending the induced G2 structure on the boundary.

Study Weyl-Einstein structures on conformal solvmanifolds, proving Einstein property and classifying metrics.

problem Characterize Weyl-Einstein structures on conformal solvmanifolds.
method Analyzing left-invariant metrics and using conformal Lie group structures.
result Every conformal solvmanifold with Weyl-Einstein structure is Einstein.

We expose a K-theoretic approach to study group C*-algebras and C*-algebraic compact quantum groups: 1. The conception of multidimensional geometric quantization and the index of group C*-algebras; 2. the entire homology of noncommutative de Rham currents and the noncommutative Chern characters, and their computation f…

1998-08-06abs ↗pdf ↗

The paper explores pp-Kähler structures on Lie group quotients.

problem Existence of pp-Kähler structures on compact quotients of Lie groups.
method Analyzes pp-Kähler structures on nilmanifolds and almost abelian solvmanifolds.
result Proves that (n2)(n-2)-Kähler almost abelian solvmanifolds of complex dimension n3n\geq3 are Kähler.

We present some examples of locally conformal symplectic structures of the first kind on compact nilmanifolds which do not admit Vaisman metrics. One of these examples does not admit locally conformal Kähler metrics and all the structures come from left-invariant locally conformal symplectic structures on the correspon…

2015-10-16abs ↗pdf ↗

We study spin structures on compact simply-connected homogeneous pseudo-Riemannian manifolds (M = G/H, g) of a compact semisimple Lie group G. We classify flag manifolds F = G/H of a compact simple Lie group which are spin. This yields also the classification of all flag manifolds carrying an invariant metaplectic stru…

2016-02-25abs ↗pdf ↗

We give a construction of integrable complex structures on the total space of a smooth principal bundle over a complex manifold, with an even dimensional compact Lie group as structure group, under certain conditions. This generalizes the constructions of complex structure on compact Lie groups by Samelson and Wang, an…

2016-03-15abs ↗pdf ↗

No left-invariant hypercomplex structures found on compact Lie groups.

problem Existence of left-invariant hypercomplex structures on compact Lie groups.
method Elementary algebraic arguments to show non-existence.
result Compact Lie groups of dimension 4n4n do not admit left-invariant hypercomplex structures.

Investigate local Lie group structure of bisections over compact manifolds

problem Study the local Lie group structure associated with the space of admissible bisections of a local Lie groupoid over a compact manifold.
method Investigate the relation of this local Lie group to the Lie algebra of sections of the associated Lie algebroid.
result Prove that the globalizability of a local Lie groupoid implies the globalizability of its associated local Lie group of bisections.

The paper explores automorphism groups of parabolic structures on aspherical manifolds.

problem Characterizing the automorphism groups of parabolic structures on aspherical manifolds.
method Analyzing properties of closed aspherical parabolic ${\sfG}$-manifolds and their automorphism groups.
result Certain parabolic ${\sfG}$-structures impose strong restrictions on the topology of compact aspherical manifolds.

In this survey, we discuss a series of linearization problems--for Poisson structures, Lie algebroids, and Lie groupoids. The last problem involves a conjecture on the structure of proper groupoids. Attempting to prove this by the method of averaging leads to problems concerning almost actions of compact groups and alm…

1999-12-22abs ↗pdf ↗

In this paper we show as main results two structure theorems of a compact homogeneous locally conformally Kaehler (or shortly l.c.K.) manifold, a holomorphic structure theorem asserting that it has a structure of holomorphic principal fiber bundle over a flag manifold with fiber a 1-dimensional complex torus, and a met…

2013-12-08abs ↗pdf ↗

In this work, we describe how to obtain the structure of an infinite-dimensional Lie group on the group of compactly carried bundle automorphisms Autc(P) for a locally convex prinicpal bundle P over a finite-dimensional smooth sigma-compact base M. This is a generalization of previous work by Wockel, where the base M w…

2013-10-31abs ↗pdf ↗

Develops scalar curvature in generalized Kahler geometry and shows constant scalar curvature on compact Lie groups.

problem Defines scalar curvature in generalized Kahler geometry.
method Introduces scalar curvature in terms of pure spinors formalism and develops a moment map framework.
result Scalar curvature is given by the moment map, generalizing results from ordinary Kahler geometry.

Study on invariant anti-quasi-Sasakian structures on compact manifolds.

problem Existence and classification of invariant anti-quasi-Sasakian structures of maximal rank.
method Analysis of invariant structures on compact homogeneous Riemannian manifolds and nilpotent Lie groups.
result Classification of invariant anti-quasi-Sasakian structures on nilpotent Lie groups.

A Z-structure on a group G, defined by M. Bestvina, is a pair (\hat{X}, Z) of spaces such that \hat{X} is a compact ER, Z is a Z-set in \hat{X}, G acts properly and cocompactly on X=\hat{X}\Z, and the collection of translates of any compact set in X forms a null sequence in \hat{X}. It is natural to ask whether a given…

2010-10-02abs ↗pdf ↗

Let G be an n-dimensional crystallographic group (n-space group). If G is a Z-reducible, then the flat n-orbifold E^n/G has a nontrivial fibered orbifold structure. We prove that this structure can be described by a generalized Calabi construction, that is, E^n/G is represented as the quotient of the Cartesian product …

2011-12-16abs ↗pdf ↗

We generalise Atiyah and Hirzebruch's vanishing theorem for actions by compact groups on compact Spin-manifolds to possibly noncompact groups acting properly and cocompactly on possibly noncompact Spin-manifolds. As corollaries, we obtain some vanishing results for A^\hat A-type genera.

2014-11-04abs ↗pdf ↗

The paper explores SKT, balanced, and generalized Kähler structures on specific Lie groups.

problem Investigating invariant SKT, balanced, and generalized Kähler structures on compact quotients of almost nilpotent Lie groups.
method Characterization and classification of Hermitian almost nilpotent Lie algebras, study of structures under flows, and non-existence results.
result Construction of new compact SKT manifolds and examples of non-split generalized Kähler structures.

We study the automorphism group of a compact 7-manifold MM endowed with a closed non-parallel G2_2-structure, showing that its identity component is abelian with dimension bounded by min{6,b2(M)}\{6,b_2(M)\}. This implies the non-existence of compact homogeneous manifolds endowed with an invariant closed non-parallel G2_2-…

2018-01-20abs ↗pdf ↗

We study the action of the group of contact diffeomorphisms on CR deformations of compact three-dimensional CR manifolds. Using anisotropic function spaces and an anisotropic structure on the space of contact diffeomorphisms, we establish the existence of local transverse slices to the action of the contact diffeomorph…

2010-07-13abs ↗pdf ↗

We present some basic results on a natural Poisson structure on any compact symmetric space. The symplectic leaves of this structure are related to the orbits of the corresponding real semisimple group on the complex flag manifold.

2002-08-06abs ↗pdf ↗