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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.

168,742 papers · 148 categories

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1223 · Mar 201719922001200920172026
48 results for Pythagorean quadruples

A quadruple crossing is a crossing in a projection of a knot or link that has four strands of the knot passing straight through it. A quadruple crossing projection is a projection such that all of the crossings are quadruple crossings. In a previous paper, it was proved that every knot and link has a quadruple crossing…

2012-11-12abs ↗pdf ↗

The paper studies a generalized Pythagorean theorem on dually flat spaces via toric geometry.

problem Understanding the geometry of dually flat spaces and their toric Kähler manifolds.
method Introducing a dually flat structure and Bregman divergence on the boundary of toric Kähler manifolds.
result A continuity and generalized Pythagorean theorem for the divergence on the boundary.

Characterizes mappings preserving Pythagorean-hodograph curves.

problem Preserving Pythagorean-hodograph curves in various dimensions.
method Proves conformal functions with square rational dilation are PH-preserving.
result Conformal functions with square rational dilation are the only PH-preserving mappings.

In the present paper, using a replica analysis, we examine the portfolio optimization problem handled in previous work and discuss the minimization of investment risk under constraints of budget and expected return for the case that the distribution of the hyperparameters of the mean and variance of the return rate of …

2017-03-08abs ↗pdf ↗

The study counts Salem numbers linked to arithmetic hyperbolic orbifolds.

problem Bounding the proportion of Salem numbers in arithmetic lattices.
method Using results on the distribution of Salem numbers, classical methods for counting Pythagorean triples, and Gauss' lattice-counting argument.
result Improved bounds on the proportion of Salem numbers and strong exponential growth of averages.

The study connects polygon areas and projective structures in 3D space.

problem Relating polygon areas and projective structures in 3D space.
method Investigates positive tuples of complete flags in R^3 and their associated polygons in RP^2.
result Establishes a relationship between Holmes-Thompson area and projective structures.

This paper constructs PH spline curves with prescribed arc lengths.

problem Interpolating points, tangent directions, and curvatures with prescribed arc-length.
method Local construction of G2G^2 planar PH biarc curves of degree 7.
result Prescribed arc-length can be satisfied for any data and any chosen ratio between boundary tangents.

A function is exponentially concave if its exponential is concave. We consider exponentially concave functions on the unit simplex. In a previous paper we showed that gradient maps of exponentially concave functions provide solutions to a Monge-Kantorovich optimal transport problem and give a better gradient approximat…

2016-05-19abs ↗pdf ↗

CPR adds entropy maximization to improve continual learning methods.

problem Catastrophic forgetting in continual learning.
method Classifier-Projection Regularization (CPR) adds an entropy maximization term to existing regularization methods.
result CPR improves accuracy and plasticity in continual learning methods.

This paper explores historical and philosophical aspects of angles and solid angles, inspired by Euler's work.

problem Understanding the historical context and philosophical implications of angles and solid angles.
method Historical review and analysis of mathematical and philosophical works.
result Questions raised by Euler about angles and solid angles are timeless and relevant to modern mathematics.

We show that a Hitchin representation is determined by the spectral radii of the images of simple, non-separating closed curves. As a consequence, we classify isometries of the intersection function on Hitchin components of dimension 3 and on the self-dual Hitchin components in all dimensions. As an important tool in t…

2017-03-21abs ↗pdf ↗

Developing a non-symmetric strainer theory for spaces with non-negative curvature beyond Alexandrov geometry.

problem Studying spaces with non-Riemannian curvature beyond Alexandrov geometry.
method Introducing a weak quadruple comparison principle and developing a strainer theory.
result Spaces have constant integer dimension, measure contraction property, and unique Banach tangent cones.

Distance functions of metric spaces with lower curvature bound, by definition, enjoy various metric inequalities; triangle comparison, quadruple comparison and the inequality of Lang-Schroeder-Sturm. The purpose of this paper is to study the extremal cases of these inequalities and to prove rigidity results. The spaces…

2009-12-01abs ↗pdf ↗

We investigate the relationship between the algebra of tensor categories and the topology of framed 3-manifolds. On the one hand, tensor categories with certain algebraic properties determine topological invariants. We prove that fusion categories of nonzero global dimension are 3-dualizable, and therefore provide 3-di…

2013-12-27abs ↗pdf ↗

New symplectic groups defined for Lie subgroups of algebras.

problem Defining new symplectic groups for Lie subgroups of algebras.
method Introducing symplectic group Sp2(G,σ)\mathrm{Sp}_2(G, σ) for Lie subgroups GG of associative algebras AA with anti-involution σσ.
result New realizations of spin groups as Sp2(G,σ)\mathrm{Sp}_2(G, σ) for suitable subgroups GG.

We consider discrete nets in Grassmannians Grd\mathbb{G}^d_r which generalize Q-nets (maps ZNPd\mathbb{Z}^N\to\mathbb{P}^d with planar elementary quadrilaterals) and Darboux nets (Pd\mathbb{P}^d-valued maps defined on the edges of ZN\mathbb{Z}^N such that quadruples of points corresponding to elementary squares are all co…

2008-12-30abs ↗pdf ↗

Let GI denote the space of all generic immersions of a surface F into a 3-manifold M. Let q(H_t) denote the number mod 2 of quadruple points of a generic regular homotopy H_t : F -> M. We are interested in defining an invariant Q : GI -> Z/2 such that q(H_t) = Q(H_0) - Q(H_1) for any generic regular homotopy H_t : F ->…

1998-08-11abs ↗pdf ↗

We classify all fusion categories for a given set of fusion rules with three simple object types. If a conjecture of Ostrik is true, our classification completes the classification of fusion categories with three simple object types. To facilitate the discussion we describe a convenient, concrete and useful variation o…

2007-04-02abs ↗pdf ↗

The present paper attempts to show an alternative approach with regards to rational Pythagorean-hodograph (PH) curves and especially more natural approach for rational PH helices (i.e. rational helices). It exploits geometric features of rational helices to obtain a simpler construction of these curves and apply this t…

2013-06-16abs ↗pdf ↗

We show a non-existence result for some class of equivariant maps between sphere bundles over tori. The notion of equivariant KO-degree is used in the proof. As an application to Seiberg-Witten theory, for a connected closed oriented spin 4-manifold with indefinite intersection form, we have a new bound of the second B…

2005-02-24abs ↗pdf ↗

Paper describes how to extend multiple conjugation quandles using maps.

problem Understanding affine extensions of multiple conjugation quandles.
method Introduces augmented MCQ Alexander pairs for affine extensions.
result Affine extensions of multiple conjugation quandles can be described by quadruples of maps.

We classify quadruples (M,g,m,τ)(M,g,m,τ) in which (M,g)(M,g) is a compact Kähler manifold of complex dimension m>2m>2 with a nonconstant function ττ on MM such that the conformally related metric g/τ2g/τ^2, defined wherever τ0τ\ne 0, is Einstein. It turns out that MM then is the total space of a holomorphic CP1CP^1 bundle over a…

2003-09-10abs ↗pdf ↗

We study the structural properties of colored Kauffman homologies of knots. Quadruple-gradings play an essential role in revealing the differential structure of colored Kauffman homology. Using the differential structure, the Kauffman homologies carrying the symmetric tensor products of the vector representation for th…

2013-10-08abs ↗pdf ↗

Let G be a simply connected, simple, complex Lie group of rank 2. We give explicit Fock-Goncharov coordinates for configurations of triples and quadruples of affine flags in G. We show that the action on triples by orientation preserving permutations corresponds to explicit quiver mutations, and that the same holds for…

2016-05-26abs ↗pdf ↗

Defines cross product for m vectors in n-dimensional spaces.

problem No universal definition for cross product in high-dimensional spaces.
method Defines cross product for m vectors in n-dimensional spaces with any metric matrices.
result Cross product length represents m-dimensional volume, components represent volume directions.

Given a surface F, we are interested in Z/2 valued invariants of immersions of F into R^3, which are constant on each connected component of the complement of the quadruple point discriminant in Imm(F,R^3). Such invariants will be called ``q-invariants.'' Given a regular homotopy class A in Imm(F,R^3), we denote by V_n…

1999-03-28abs ↗pdf ↗

Rényi divergence is related to Rényi entropy much like Kullback-Leibler divergence is related to Shannon's entropy, and comes up in many settings. It was introduced by Rényi as a measure of information that satisfies almost the same axioms as Kullback-Leibler divergence, and depends on a parameter that is called its or…

2012-06-12abs ↗pdf ↗

The torus T=S1×S1\mathbb{T}=S^1\times S^1 appears as the ideal boundary AdS3\partial_\infty AdS^3 of the three-dimensional anti-de Sitter space AdS3AdS^3, as well as the Fürstenberg boundary F(X)\mathbb{F}(X) of the rank-2 symmetric space X=SO0(2,2)/SO(2)×SO(2)X={\rm SO}_0(2,2)/{\rm SO}(2)\times{\rm SO}(2). We introduce cross-ratios on the torus in …

2017-03-15abs ↗pdf ↗

Study geometric formal metrics and Massey products on Kähler manifolds with torsion.

problem Interplay between geometrically-Bott-Chern-formal metrics and SKT metrics on Kähler manifolds.
method Analyzing nilmanifolds and Kähler solvmanifolds, proving conditions for existence of SKT metrics and Massey products.
result Any Kähler solvmanifold is geometrically formal, and explicit constructions of lattices with non-vanishing Massey products.

The paper derives upper bounds on eigenvalues of Laplace-Beltrami operator on hyperbolic surfaces.

problem Finding upper bounds on eigenvalues of Laplace-Beltrami operator on hyperbolic surfaces.
method Using spectral decompositions and consistency conditions derived from quadruple overlap integrals in terms of triple overlap integrals.
result Derives upper bounds on eigenvalues, nearly saturated by the Bolza surface.

Computes deformations of parabolic structures on Riemann surfaces.

problem Infinitesimal deformations of parabolic connections and opers.
method Computes infinitesimal deformations of quadruples (X, S, E*, D) and (X, S, D).
result Monodromy map is an immersion from the moduli space of triples to the character variety.

Geodesic connectedness proved for statistical manifolds with divisible cubic forms.

problem Geodesic connectedness of affine connections on statistical manifolds with divisible cubic forms.
method Analogy with Hopf-Rinow theorem in Riemannian geometry, establishing geodesic completeness.
result Geodesic connectedness established for statistical manifolds with divisible cubic forms.

Deep learning models can initially degrade in performance as they grow larger, then improve.

problem Performance degradation of larger models and more data.
method Defined effective model complexity and identified double descent phenomenon.
result Increasing model size and data can initially hurt performance, contrary to intuition.

The following results are proved: Theorem 1. A totally real semiparallel submanifold of constant curvature with parallel f-structure in the normal bundle of a Kähler manifold N is flat or a totally geodesic submanifold of N. Theorem 2. A totally real minimal semiparallel submanifold M with parallel f-structure in the n…

2010-10-08abs ↗pdf ↗