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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.

168,695 papers · 148 categories

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58116174232 · May 202619922001200920172026
48 results for flat Lie group

This paper deals essentially with affine or projective transformations of Lie groups endowed with a flat left invariant affine or projective structure. These groups are called flat affine or flat projective Lie groups. Our main results determine Lie groups admitting flat bi-invariant affine or projective structures. Th…

2014-08-31abs ↗pdf ↗

A Lorentzian flat Lie group is a Lie group GG with a flat left invariant metric μμ with signature (1,n1)=(,+,,+)(1,n-1)=(-,+,\ldots,+). The Lie algebra g=TeG\mathfrak{g}=T_eG of GG endowed with   ,  =μ(e)\langle\;,\;\rangle=μ(e) is called flat Lorentzian Lie algebra. It is known that the metric of a flat Lorentzian Lie group is geodesical…

2014-01-05abs ↗pdf ↗

We give a new characterization of flat affine manifolds in terms of an action of the Lie algebra of classical infinitesimal affine transformations on the bundle of linear frames. We characterize flat affine symplectic Lie groups using symplectic étale affine representations and as a consequence of this, we show that a …

2019-02-05abs ↗pdf ↗

In these notes we survey basic concepts of affine geometry and their interaction with Riemannian geometry. We give a characterization of affine manifolds which has as counterpart those pseudo-Riemannian manifolds whose Levi-Civita connection is flat. We show that no connected semisimple Lie group admits a left invarian…

2019-03-21abs ↗pdf ↗

To determine the Lie groups that admit a flat (eventually complete) left invariant semi-Riemannian metric is an open and difficult problem. The main aim of this paper is the study of the flatness of left invariant semi Riemannian metrics on quadratic Lie groups i.e. Lie groups endowed with a bi-invariant semi Riemannia…

2011-03-07abs ↗pdf ↗

We call the Lie algebra of a Lie group with a left invariant pseudo-Riemannian flat metric pseudo-Riemannian flat Lie algebra. We give a new proof of a classical result of Milnor on Riemannian flat Lie algebras. We reduce the study of Lorentzian flat Lie algebras to those with trivial center or those with degenerate ce…

2011-03-03abs ↗pdf ↗

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.

We introduce a combinatorial method to construct indefinite Ricci-flat metrics on nice nilpotent Lie groups. We prove that every nilpotent Lie group of dimension 6\leq6, every nice nilpotent Lie group of dimension 7\leq7 and every two-step nilpotent Lie group attached to a graph admits such a metric. We construct inf…

2019-08-16abs ↗pdf ↗

The paper constructs a new Ricci-flat metric on almost abelian Lie groups.

problem Finding Lorentzian homogeneous Ricci-flat metrics on almost abelian Lie groups.
method Constructing left-invariant metrics on almost abelian Lie groups, focusing on dimensions four or higher.
result A new Ricci-flat metric that generalizes the Petrov solution to higher dimensions.

Semisimple Lie groups act transitively on pseudo-Riemannian manifolds, making them flat.

problem Understanding actions of semisimple Lie groups on pseudo-Riemannian manifolds.
method Analyzing the pseudo-Riemannian Lichnerowicz conjecture in homogeneous settings.
result Compact pseudo-Riemannian manifolds on which a semisimple group acts conformally, essentially and transitively, are conformally flat.

In this paper we exhibit a family of flat left invariant affine structures on the double Lie group of the oscillator Lie group of dimension 4, associated to each solution of classical Yang-Baxter equation given by Boucetta and Medina. On the other hand, using Koszul's method, we prove the existence of an immersion of L…

2017-10-04abs ↗pdf ↗

Characterizes hypercomplex Lie groups and their solvmanifolds.

problem Understanding hypercomplex structures on Lie groups and their solvmanifolds.
method Characterization of almost abelian Lie groups with hypercomplex structures, analysis of Obata and Bismut connections, classification of hypercomplex Lie groups, and construction of solvmanifolds.
result Classification of hypercomplex almost abelian Lie groups in dimension 8 and properties of their solvmanifolds.

We determine all Ricci flat left invariant Lorentzian metrics on simply connected 2-step nilpotent Lie groups. We show that the 2k+12k+1-dimensional Heisenberg Lie group H2k+1H_{2k+1} carries a Ricci flat left invariant Lorentzian metric if and only if k=1k=1. We show also that for any 2qk2\leq q\leq k, H2k+1H_{2k+1} carries a R…

2009-10-14abs ↗pdf ↗

Study the spaces of flat connections for classical Lie groups using Chern-Weil theory.

problem Understanding the weak homotopy type of spaces of flat connections for classical Lie groups.
method Use Chern-Weil theory and relate to the functorial map involving continuous families of representations.
result Relate the spaces of flat connections to the weak homotopy type of the spaces of representations.

We establish the existence of solvable Lie groups of dimension 4 and left-invariant Riemannian metrics with zero Bach tensor which are neither conformally Einstein nor half conformally flat.

2013-03-19abs ↗pdf ↗

Half-flat SU(3)-structures are the natural initial values for Hitchin's evolution equations whose solutions define parallel G_2-structures. Together with the results of arXiv:0912.3486v1, the results of this article completely solve the existence problem of left-invariant half-flat SU(3)-structures on decomposable Lie …

2010-12-16abs ↗pdf ↗

New findings on Chern flat metrics and their criticality.

problem Understanding critical Hermitian metrics on Chern flat manifolds.
method Analyzing Chern flat manifolds as compact quotients of complex Lie groups and studying their criticality.
result Chern flat metrics on semi-simple Lie groups are torsion-critical and vice versa.

Study para-complex structures on specific Lie groups, finding explicit forms and properties.

problem Characterizing para-Kähler structures on six-dimensional nilpotent Lie groups.
method Examined left-invariant para-complex structures on six-dimensional nilpotent Lie groups, obtained explicit expressions and investigated curvature properties.
result Para-complex structures are nilpotent and para-Kähler metrics are Ricci-flat.

We classify solvable Lie groups admitting left invariant symplectic half-flat structure. When the Lie group has a compact quotient by a lattice, we show that these structures provide solutions of supersymmetric equations of type IIA.

2011-11-17abs ↗pdf ↗

This is partly an expository paper, where the authors' work on pseudoriemannian Einstein metrics on nilpotent Lie groups is reviewed. A new criterion is given for the existence of a diagonal Einstein metric on a nice nilpotent Lie group. Classifications of special classes of Ricci-flat metrics on nilpotent Lie groups o…

2018-12-04abs ↗pdf ↗

We prove that any base space of Riemannian submersion from a compact Lie group (with bi-invariant metric) must have a basic property previously known for normal biquotients; namely, any zero-curvature plane exponentiates to a flat.

2007-03-13abs ↗pdf ↗

Defines and extends flat pseudo-Riemannian F-Lie algebras.

problem Generating weakly flat Lorentzian non-abelian bi-nilpotent F-Lie algebras.
method Constructs double extensions of flat pseudo-Riemannian F-Lie algebras.
result Provides a framework for generating all weakly flat Lorentzian non-abelian bi-nilpotent F-Lie algebras.

Study Lie bialgebra structures on flat metric Lie algebras, leading to explicit Poisson-Lie groups.

problem Understanding Lie bialgebra structures on flat metric Lie algebras.
method Splitting Lie algebras, establishing normal forms, and using invariant Schouten squares.
result Explicit construction of multiplicative Poisson tensors on flat Poisson-Lie groups.

Post-Lie algebra structure found on non-flat manifolds with curvature and torsion.

problem Understanding vector fields and endomorphisms on manifolds with curvature and torsion.
method Analyzing the post-Lie algebra structure of vector fields and endomorphisms for non-flat connections.
result A universal Lie algebra is constructed for the post-Lie algebra of vector fields and endomorphisms.

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.

We give a characterization of flat affine connections on manifolds by means of a natural affine representation of the universal covering of the Lie group of diffeomorphisms preserving the connection. From the infinitesimal point of view, this representation is determined by the 1-connection form and the fundamental for…

2019-10-09abs ↗pdf ↗

With a f-left-invariant Riemannian metric on a Lie group GG, we mean a Riemannian metric which is conformally equivalent to a left-invariant Riemannian metric, with the conformal factor ff. In this article, we study the geometry of such metrics and give a necessary and sufficient condition for an f-left-invariant Rie…

2014-01-03abs ↗pdf ↗

We investigate contact Lie groups having a left invariant Riemannian or pseudo-Riemannian metric with specific properties such as being bi-invariant, flat, negatively curved, Einstein, etc. We classify some of such contact Lie groups and derive some obstruction results to the existence of left invariant contact structu…

2014-02-20abs ↗pdf ↗