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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.

169,051 papers · 148 categories

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48 results for natural product structure

A Riemannian almost product manifold with integrable almost product structure is called a Riemannian product manifold. In the present paper the natural connections on such manifolds are studied, i.e. the linear connections preserving the almost product structure and the Riemannian metric.

2011-01-31abs ↗pdf ↗

No conformal product structures on compact manifolds with constant curvature.

problem Existence of conformal product structures on compact manifolds with constant curvature.
method Analyzing non-flat manifolds and irreducible, compact locally symmetric spaces of non-positive curvature.
result Compact non-flat manifolds with constant sectional curvature admit no conformal product structure.

Noting that the complete lift of a Rimannian metric defined on a differentiable manifold is not 0-homogeneous on the fibers of the tangent bundle . In this paper we introduce a new lift which is 0-homogeneous. It determines on slit tangent bundle a pseudo-Riemannian metric, which depends only on the metric . We study s…

2007-10-20abs ↗pdf ↗

Local Poisson groupoids over mixed product Poisson structures defined and applied.

problem Defining and studying Poisson structures on groupoids.
method Using a local Lagrangian bisection in a double symplectic groupoid to twist a direct product of Poisson groupoids.
result Proving Gu,uG^{u,u} is a Poisson groupoid over OuO^u.

New product structures encode superintegrable Hamiltonian systems in Euclidean spaces.

problem Encoding superintegrable Hamiltonian systems using product structures.
method Introducing commutative and associative product structures on Euclidean spaces of dimension at least three, satisfying specific conditions.
result All abundant superintegrable Hamiltonian systems on Euclidean space of dimension at least three arise from these product structures.

The geometric product, defined by Graf on the space of differential forms, endows the sections of the exterior bundle by a structure that is necessary to construct a Clifford algebra. The Graf product is introduced and revisited with a suitable underlying framework that naturally encompasses a coframe in the cotangent …

2017-12-06abs ↗pdf ↗

Generalizes pseudo-product structures with abnormal extremals.

problem Finiteness of symmetry algebras for non-degenerate pseudo-product structures.
method Modified universal prolongation of graded nilpotent Lie algebras and generalized finiteness criterion.
result Distributions with singularly transitive properties have finite-dimensional symmetries.

We determine the structure of the *-Lie superalgebra generated by a set of carefully chosen natural operators of an orientable WSD manifold of rank three. This Lie superalgebra is formed by global sections of a natural Lie superalgebra bundle, and turns out to be a product of $\mathbf{sl}(4,\C)$ with the full special…

2007-06-07abs ↗pdf ↗

Study CR submanifolds of nearly Kähler S³ × S³ using properties of its almost product structure.

problem Characterize CR submanifolds of nearly Kähler S³ × S³.
method Analyze CR submanifolds in relation to the canonical almost product structure on vector bundles.
result Identify key properties of CR submanifolds related to the almost product structure.

The tensor-tensor product (t-product) [M. E. Kilmer and C. D. Martin, 2011] is a natural generalization of matrix multiplication. Based on t-product, many operations on matrix can be extended to tensor cases, including tensor SVD, tensor spectral norm, tensor nuclear norm [C. Lu, et al., 2018] and many others. The line…

2018-06-17abs ↗pdf ↗

Integrability conditions for complex structures on product twistor spaces linked to Weyl geometry.

problem Integrability conditions for complex structures on product twistor spaces.
method Using Hitchin's generalized geometry and a metric connection with skew-symmetric torsion, the integrability conditions are derived in terms of Weyl geometry.
result Examples of structures satisfying the integrability conditions are supplied.

Observation of the workings of productive organizations shows that the characteristics of a trade, backed by nature given to a technological environment, determine the productive combination implemented by the decision maker, and the structure of the operating cycle which is related. The choice of the production functi…

2012-02-09abs ↗pdf ↗

The paper establishes isomorphisms between different versions of intersection homology duality and products.

problem Comparing and relating different versions of intersection homology duality and products.
method Sheaf-theoretic and singular chain methods, PL pseudomanifolds, and de Rham isomorphism.
result Isomorphisms between sheaf-theoretic and singular intersection homology duality and products.

We consider higher dimensional generalisations of normal almost contact structures, the so called f.pk-structures where parallelism spans a Lie algebra g (f.pk-g-structures). Two types of these structures are discussed. In the first case, we construct an almost complex structure on a product manifold mirroring K-struct…

2016-09-27abs ↗pdf ↗

Geodesic orbit nilmanifolds linked to graph structures.

problem Characterizing Riemannian nilmanifolds associated with graphs.
method Analyzing naturally reductive and geodesic orbit properties of nilmanifolds defined by graphs.
result Nilmanifolds are geodesic orbit if and only if naturally reductive if and only if the defining graph is a disjoint union of complete graphs.

We prove that the only natural differential operations between holomorphic forms on a complex manifold are those obtained using linear combinations, the exterior product and the exterior differential. In order to accomplish this task we first develop the basics of the theory of natural holomorphic bundles over a fixed …

2016-10-14abs ↗pdf ↗

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 ↗

What are East Africa's industrial opportunities? In this article we explore this question by using the Product Space to study the productive structure of five south-east African countries: Kenya, Mozambique, Rwanda, Tanzania and Zambia. The Product Space is a network connecting products that tend to be exported by the …

2012-03-01abs ↗pdf ↗

The main result of this paper states that a symplectic s-cobordism of elliptic 3-manifolds is diffeomorphic to a product (assuming a canonical contact structure on the boundary). Based on this theorem, we conjecture that a smooth s-cobordism of elliptic 3-manifolds is smoothly a product if its universal cover is smooth…

2004-03-23abs ↗pdf ↗

We investigate manifolds obtained as a quotient of a doubly warped product. We show that they are always covered by the product of two suitable leaves. This allows us to prove, under regularity hypothesis, that these manifolds are a doubly warped product up to a zero measure subset formed by an union of leaves. We also…

2009-05-29abs ↗pdf ↗

Simply-connected 4-manifolds are covered by products with a 2-torus.

problem Proving that any closed simply-connected smooth 4-manifold is branched covered by a product of an orientable surface and a 2-torus.
method Natural construction with respect to spin structures, solving Problem 4.113(C) in Kirby's list.
result Closed simply-connected smooth 4-manifolds are 16-fold branched covered by a product of an orientable surface and a 2-torus.

Let g\mathfrak{g} be a Lie algebra, EE a vector space containing g\mathfrak{g} as a subspace. The paper is devoted to the \emph{extending structures problem} which asks for the classification of all Lie algebra structures on EE such that g\mathfrak{g} is a Lie subalgebra of EE. A general product, called the unifi…

2013-01-23abs ↗pdf ↗

The class W_1 of conformal Riemannian P-manifolds is the largest class of Riemannian almost product manifolds, which is closed with respect to the group of the conformal transformations of the Riemannian metric. This class is an analogue of the class of conformal Kaehler manifolds in almost Hermitian geometry. In the p…

2011-09-13abs ↗pdf ↗

We consider manifolds endowed with a contact pair structure. To such a structure are naturally associated two almost complex structures. If they are both integrable, we call the structure a normal contact pair. We generalize the Morimoto's Theorem on product of almost contact manifolds to flat bundles. We construct som…

2008-05-02abs ↗pdf ↗

Deform moment map on symplectic connections using star product algebras.

problem Understanding symplectic connections and their deformations.
method Study vector bundle of Fedosov star product algebras, formal connection, curvature, and star product trace.
result Showed star product trace as a formal symplectic form and moment map.

We initiate the study of the generalized quaternionic manifolds by classifying the generalized quaternionic vector spaces, and by giving two classes of nonclassical examples of such manifolds. Thus, we show that any complex symplectic manifold is endowed with a natural (nonclassical) generalized quaternionic structure,…

2011-09-29abs ↗pdf ↗

Product Kanerva Machines dynamically combine smaller models for better memory organization.

problem Limited organization in the Kanerva Machine.
method Introducing Product Kanerva Machines that dynamically combine multiple smaller Kanerva Machines.
result Product Kanerva Machines can discover spatial tunings that approximately factorize simple images by object.