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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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48 results for Almost Abelian groups

Harmonic almost complex structures on specific Lie groups and solvmanifolds identified.

problem Characterizing harmonic almost complex structures on almost abelian Lie groups and solvmanifolds.
method Adapted Gray-Hervella classification to almost abelian Lie groups, characterized harmonic structures.
result Examples of harmonic almost complex structures in different Gray-Hervella classes on compact almost abelian solvmanifolds.

The paper classifies invariant structures on complex almost Abelian groups.

problem Investigating invariant geometric structures on almost Abelian Lie groups.
method Explicit formulas for Haar measures, modular function, and generator fields were derived.
result All invariant tensor fields have constant coefficients in the invariant frame.

Study on CKY forms on almost abelian Lie groups, proving parallelism and characterizing non-parallel cases.

problem Characterizing CKY forms on almost abelian Lie groups and proving parallelism.
method Analyzing almost abelian metric Lie algebras, proving parallelism for CKY forms, and classifying cases up to dimension 5.
result CKY forms are parallel on almost abelian Lie algebras, with exceptions for p=1p=1 and p=n1p=n-1.

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.

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.

Study locally conformally balanced metrics on specific Lie algebras.

problem Characterize and classify locally conformally balanced metrics on almost abelian Lie algebras.
method Characterizations and classifications based on specific properties of Lie algebras.
result Classification of six-dimensional almost abelian Lie algebras with locally conformally balanced metrics.

New examples show non-abelian fundamental groups for positive Ricci curvature manifolds.

problem Constructing manifolds with positive Ricci curvature and non-abelian fundamental groups.
method Constructing specific 9-dimensional manifolds with positive Ricci curvature and non-uniformly virtually abelian fundamental groups.
result Examples of manifolds with positive Ricci curvature and non-uniformly virtually abelian fundamental groups.

Study balanced Hermitian structures on almost abelian Lie algebras, classifying six-dimensional cases.

problem Classify balanced Hermitian structures on almost abelian Lie algebras.
method Classify six-dimensional almost abelian Lie algebras with balanced structures, investigate flow of balanced metrics and anomaly flow.
result Prove conjecture for compact almost abelian solvmanifolds with left-invariant complex structures.

For certain manifolds, nonnegative Ricci curvature limits dimension and forces almost abelian fundamental group.

problem Bounding the dimension of manifolds with nonnegative Ricci curvature and specific fundamental group properties.
method Dimensional estimates for RCD(0,N)\mathrm{RCD}(0,N) spaces with large Hausdorff dimension.
result If dimension is less than 12, the fundamental group is almost abelian.

Characterizes almost Abelian Lie algebras with special HH-structures.

problem Identifying almost Abelian Lie algebras with torsion-free HH-structures.
method Using linear maps and endomorphisms, characterizes the subspace of ff for which the Lie algebra admits a special HH-structure.
result Explicitly computes the subspace of ff for various linear Lie groups HH.

We find explicit solutions of the Laplacian coflow of G2G_2-structures on seven-dimensional almost-abelian Lie groups. Moreover, we construct new examples of solitons for the Laplacian coflow which are not eigenforms of the Laplacian and we exhibit a solution, which is not a soliton, having a bounded interval of existe…

2017-11-10abs ↗pdf ↗

The paper classifies hypercomplex Lie algebras and solvmanifolds using quaternionic Jordan form.

problem Classifying hypercomplex Lie algebras and solvmanifolds.
method Application of quaternionic Jordan form to Lie algebras and solvmanifolds.
result Infinitely many hypercomplex almost abelian solvmanifolds constructed.

Study of abelian structures on odd-dimensional Lie algebras and their geometric properties.

problem Characterizing abelian structures on odd-dimensional Lie algebras.
method Introducing and analyzing abelian almost contact and almost 3-contact structures, and their compatibility conditions.
result Classification of 5-dimensional Sasakian Lie algebras and 7-dimensional abelian almost 3-contact Lie algebras.

The note confirms a conjecture for specific Lie groups.

problem The conjecture about constant holomorphic sectional curvature in non-Kähler geometry.
method Compact quotients of Lie groups with specific properties.
result The conjecture is confirmed for almost abelian Lie algebras and those with certain abelian ideals.

New representation theory for surface groups to SO0(2,3).

problem Understanding representations of surface groups into special orthogonal groups.
method Non-maximal Anosov representations via Higgs bundles and non-Abelian Hodge correspondence.
result Generalization of Filip's result on weight 3 variation of Hodge structures.

Locally conformal SKT structures are introduced and studied on Lie groups and their compact quotients.

problem Existence and classification of LCSKT structures on Lie groups and their quotients.
method Introducing LCSKT structures and studying their properties on Lie groups and their quotients.
result Existence of non-trivial LCSKT structures on 6-dimensional nilpotent Lie algebras and almost abelian Lie algebras.

We prove that a fundamental group of codimension one nonnegative Ricci curvature C2-foliation of a closed Riemannian manifold is finitely generated and almost abelian, i.e. it contains abelian subgroup of finite index. In particular, we confirm the Milnor conjecture for manifolds which are leaves of codimension one non…

2017-11-13abs ↗pdf ↗

Classifies complex symplectic structures on Lie algebras with large abelian ideals.

problem Classifying complex symplectic structures on Lie algebras with large abelian ideals.
method Two constructions of complex symplectic structures on Lie algebras with large abelian ideals, considering compact quotients of Lie groups.
result Complete classification of complex symplectic structures on almost abelian Lie algebras.

Study of presymplectic forms on almost abelian Lie algebras, determining moduli spaces and their finiteness.

problem Determining conditions for the existence of presymplectic forms on almost abelian Lie algebras.
method Analyzing the moduli space of presymplectic forms and using matrix congruence to find canonical representatives.
result The moduli space of presymplectic forms on almost abelian Lie algebras is finite and all forms are permutations of a canonical 2-form.

Study characterizes G2G_2-structures on specific Lie groups and identifies harmonic conditions.

problem Characterizing and identifying harmonic G2G_2-structures on almost Abelian Lie groups.
method Analyzing left-invariant G2G_2-structures, characterizing torsion forms, and using algebraic conditions.
result Established algebraic conditions for harmonic G2G_2-structures and identified admissible torsion classes.

We study the cohomology properties of the singular foliation $\F$ determined by an action Φ ⁣:G×MMΦ\colon G \times M\to M where the abelian Lie group GG preserves a riemannian metric on the compact manifold MM. More precisely, we prove that the basic intersection cohomology $\lau{\IH}{*}{\per{p}}{\mf}$ is finite dimensiona…

2004-01-28abs ↗pdf ↗

We study the spinor flow on homogeneous spin manifolds. After providing the general setup we discuss the homogeneous spinor flow in dimension 3 and on almost abelian Lie groups in detail. As a further example the flag manifold in dimension 6 is treated.

2018-11-06abs ↗pdf ↗

Given a non compact semisimple Lie group GG we describe all homogeneous spaces G/LG/L carrying an invariant almost Kähler structure (ω,J)(ω,J). When LL is abelian and GG is of classical type, we classify all such spaces which are Chern-Einstein, i.e. which satisfy ρ=λωρ= λω for some λRλ\in\mathbb R, where ρρ is the Ricci…

2018-11-09abs ↗pdf ↗

A Theorem of Kirichenko states that the torsion 3-form of the characteristic connection of a nearly Kähler manifold is parallel. On the other side, any almost hermitian manifold of type G1\mathrm{G}_1 admits a unique connection with totally skew symmetric torsion. In dimension six, we generalize Kirichenko's Theorem an…

2004-03-08abs ↗pdf ↗

Abstract classifies Lie algebras with complex or symplectic structures.

problem Classifying Lie algebras with specific structures.
method Analyzing Jordan normal form and restrictions on matrix AA.
result Classification reduces to nilpotent case, with specific structure implications.

The paper proves a conjecture about the positivity of the Euler characteristic for complex projective manifolds.

problem Proving the positivity of the Euler characteristic for complex projective manifolds with large fundamental groups.
method Introducing a vanishing cycle functor of multivalued one-forms and applying non-abelian Hodge theory techniques.
result The paper proves a stronger statement about the positivity of the Euler characteristic for complex projective manifolds with large fundamental groups and almost faithful linear representations.

The paper proves a transformation theorem under a monotone property of almost Euclidean factors of geodesic balls.

problem The non-increasing property of numbers of almost Euclidean factors of geodesic balls.
method Proves a transformation theorem under a non-decreasing property compared to the non-increasing property.
result Shows that for a manifold with nonnegative Ricci curvature, if its universal cover is polar at infinity and the number of almost Euclidean factors is monotone, then its fundamental group is finitely generated and virtually abelian.

We describe an action of the concordance group of knots in the three-sphere on concordances of knots in arbitrary 3-manifolds. As an application we define the notion of almost-concordance between knots. After some basic results, we prove the existence of non-trivial almost-concordance classes in all non-abelian 3-manif…

2016-02-17abs ↗pdf ↗

The paper shows that certain manifolds with nonnegative Ricci curvature have finitely generated fundamental groups.

problem Understanding fundamental groups of manifolds with nonnegative Ricci curvature.
method Proving finite generation of fundamental groups under specific curvature and cover conditions.
result The fundamental group of the manifold is finitely generated under given conditions.

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.

In this article, we determine the seven-dimensional almost Abelian Lie algebras which admit calibrated or parallel G_2-/G_2^*-structures. Along the way, we show that certain well-established curvature restrictions for calibrated and parallel G_2-structures are not valid in the G_2^* case. In more detail, we provide the…

2013-07-09abs ↗pdf ↗