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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.

168,657 papers · 148 categories

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1234 · Nov 201919922001200920172026
48 results for radical

Social Media has influenced the way people socially connect, interact and opinionize. The growth in technology has enhanced communication and dissemination of information. Unfortunately,many terror groups like jihadist communities have started consolidating a virtual community online for various purposes such as recrui…

2019-07-22abs ↗pdf ↗

Consider a smooth manifold with a smooth metric which changes bilinear type from Riemann to Lorentz on a hypersurface ΣΣ with radical tangent to ΣΣ. Two natural bilinear symmetric forms appear there, and we use it to analyze the geometry of ΣΣ. We show the way in which these forms control the smooth extensibility ov…

2003-06-10abs ↗pdf ↗

We prove that every Kaehler solvmanifold has a finite covering whose holomorphic reduction is a principal bundle. An example is given that illustrates the necessity, in general, of passing to a proper covering. We also answer a stronger version of a question posed by Akhiezer for homogeneous spaces of nonsolvable algeb…

2007-01-31abs ↗pdf ↗

In this paper we study curvature properties of semi-symmetric type of totally umbilical radical transversal lightlike hypersurfaces (M,g)(M,g) and (M,g~)(M,\widetilde g) of a Kähler-Norden manifold (M,J,g,g~)(\overline M,\overline J,\overline g,\overline {\widetilde g}) of constant totally real sectional curvatures ν\overline ν and …

2014-07-25abs ↗pdf ↗

Paper introduces a new symbol map for differential symmetry breaking operators.

problem Generalizing the symbol map to non-abelian settings.
method Introduces and studies the truncated symbol map Symb0(D)\mathrm{Symb}_0(\mathbb{D}).
result Classified and constructed differential intertwining operators and homomorphisms.

Let MM be a simply connected pseudo-Riemannian homogeneous space of finite volume with isometry group GG. We show that MM is compact and that the solvable radical of GG is abelian and the Levi factor is a compact semisimple Lie group acting transitively on MM. For metric index less than three, we find that the iso…

2018-07-06abs ↗pdf ↗

On a Riemannian or a semi-Riemannian manifold, the metric determines invariants like the Levi-Civita connection and the Riemann curvature. If the metric becomes degenerate (as in singular semi-Riemannian geometry), these constructions no longer work, because they are based on the inverse of the metric, and on related o…

2011-05-01abs ↗pdf ↗

This paper shows the reduced characteristic group of Lie LCP manifolds is simply connected.

problem Understanding the structure of Lie LCP manifolds and their characteristic groups.
method Restricting the action of the fundamental group to the non-flat factor of the universal cover and taking the connected component of the identity in the closure of this restriction.
result The reduced characteristic group of any Lie LCP manifold is simply connected.

Study explores solvable Lie groups' actions on closed Lorentzian manifolds.

problem Understanding conformal actions of solvable Lie groups on closed Lorentzian manifolds.
method Analyzes the identity component of the conformal group and uses algebraic hypotheses.
result Establishes conditions for conformal flatness and local embeddings.

The paper deals with regression problems, in which the nonsmooth target is assumed to switch between different operating modes. Specifically, piecewise smooth (PWS) regression considers target functions switching deterministically via a partition of the input space, while switching regression considers arbitrary switch…

2017-07-25abs ↗pdf ↗

In this paper we generalize harmonic maps and morphisms to the \emph{degenerate semi-Riemannian category}, in the case when the manifolds MM and NN are \emph{stationary} and the map φ:MNφ:M\to N is \emph{radical-preserving}. We characterize geometrically the notion of \emph{(generalized) horizontal (weak) conformality}…

2003-03-21abs ↗pdf ↗

Local norms of Fourier multipliers bounded on discrete subgroups of Lie groups.

problem Bounding LpL_p norms of Fourier multipliers on discrete subgroups of Lie groups.
method Developed tools to find explicit bounds on c(A)c(A), reducing the problem to representations of semisimple and radical parts of Lie algebras.
result Explicit bounds on c(A)c(A) for unimodular connected solvable Lie groups, showing c(G)=1c(G) = 1.

In this work, we give a formula for the logarithmic invariant of knots in terms of certain derivatives of the colored Jones invariant. This invariant is related to the logarithmic conformal field theory, and was defined by using the centers in the radical of the restricted quantum group at root of unity. A relation bet…

2014-06-05abs ↗pdf ↗

This paper studies lightlike Cartan geometries and their properties.

problem Understanding geometric structures on lightlike cones in spacetime.
method Develops Cartan geometries on the future lightlike cone of Lorentz-Minkowski spacetime.
result Lightlike Cartan geometries induce a lightlike metric and compatible structures.

Study automorphism group actions on Jacobi diagrams spaces.

problem Understanding automorphism group actions on Jacobi diagrams.
method Using actions of GL(n,Z) and IA-automorphism group Lie algebra, extend to Andreadakis filtration.
result Obtained indecomposable decomposition and radical filtration of Jacobi diagrams spaces.

The Golden Ratio is fascinating topic that continually generated news ideas. A Riemannian manifold endowed with a Golden Structure will be called a Golden Riemannian manifold. The main purpose of the present paper is to study the geometry of radical transversal lightlike submanifolds and transversal lightlike submanifo…

2018-04-10abs ↗pdf ↗

We investigate the existence of left-invariant closed G2_2-structures on seven-dimensional non-solvable Lie groups, providing the first examples of this type. When the Lie algebra has trivial Levi decomposition, we show that such a structure exists only when the semisimple part is isomorphic to $\mathfrak{sl}(2,\mathb…

2017-12-27abs ↗pdf ↗

Study on umbilical submanifolds in specific geometric spaces.

problem Characterizing curvature properties of umbilical submanifolds.
method Analyzing totally and screen totally umbilical half lightlike submanifolds in almost contact B-metric manifolds.
result Curvature properties of these submanifolds were studied and characterized.

We describe a novel optimization method for finite sums (such as empirical risk minimization problems) building on the recently introduced SAGA method. Our method achieves an accelerated convergence rate on strongly convex smooth problems. Our method has only one parameter (a step size), and is radically simpler than o…

2016-02-08abs ↗pdf ↗

Locally, a screen integrable globally null manifold MM splits through a Riemannian leaf MM' of its screen distribution and a null curve C\mathcal{C} tangent to its radical distribution. The leaf MM' carries a lot of geometric information about MM and, in fact, forms a basis for the study of expanding and non-expan…

2019-08-01abs ↗pdf ↗

The aim of the present article is to treat the Greek public debt issue strictly as a curve fitting problem. Thus, based on Eurostat data and using the Mathematica technical computing software, an exponential function that best fits the data is determined modelling how the Greek public debt expands with time. Exploring …

2012-12-07abs ↗pdf ↗

Clustering is an essential data mining tool that aims to discover inherent cluster structure in data. For most applications, applying clustering is only appropriate when cluster structure is present. As such, the study of clusterability, which evaluates whether data possesses such structure, is an integral part of clus…

2018-08-24abs ↗pdf ↗

This paper proves a conjecture of Fomin and Shapiro that their combinatorial model for any Bruhat interval is a regular CW complex which is homeomorphic to a ball. The model consists of a stratified space which may be regarded as the link of an open cell intersected with a larger closed cell, all within the totally non…

2007-11-08abs ↗pdf ↗

Consider a smooth manifold MM with a smooth cometric gg^{\ast} which changes the bilineal type by transverse way, on a hypersurface DD^{\infty}. Suppose that the radical annihilator hyperplane is tangent to DD^{\infty}. We examine the geometry of the (gg^{\ast}-dual) covariant metric gg on MM- DD^{\infty}, prov…

2006-06-02abs ↗pdf ↗

If XX is an orientable, strongly minimal PD4PD_4-complex and π1(X)π_1(X) has one end then it has no nontrivial locally-finite normal subgroup. Hence if ππ is a 2-knot group then (a) if ππ is virtually solvable then either ππ has two ends or πΦπ\congΦ, with presentation a,tta=a2t\langle{a,t}|ta=a^2t\rangle, or ππ is torsion-f…

2016-10-20abs ↗pdf ↗

We consider, for each smooth manifold MM, the set M\mathbb{M} comprised by all the primary ideals of C(M)\mathcal{C}^\infty(M) which are closed and whose radical is maximal. The classical Lie theory of jets (jets of submanifolds) must be extended to M\mathbb{M} in order to have nice functorial properties. We will begi…

2016-10-31abs ↗pdf ↗

Researchers calculate Morse index and nullity for two specific minimal hypersurfaces.

problem Calculating Morse index and nullity for homogeneous minimal hypersurfaces with g=4g = 4 or 66.
method Analyzing two specific homogeneous minimal hypersurfaces in SnS^n with g=4g = 4.
result Obtained irrational eigenvalues in Laplace spectra for the two hypersurfaces.