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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.

168,742 papers · 148 categories

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96191287382 · Jun 202019922001200920172026
48 results for Locally convex Fréchet lattice

The asymptotic concentration of the Fr{é}chet mean of IID random variables on a Rieman-nian manifold was established with a central limit theorem by Bhattacharya \& Patrangenaru (BP-CLT) [6]. This asymptotic result shows that the Fr{é}chet mean behaves almost as the usual Euclidean case for sufficiently concentrated di…

2019-06-18abs ↗pdf ↗

The paper introduces new geometric methods to analyze radar electromagnetic wave statistics.

problem Analyzing spatio-temporal and polarimetric fluctuations of radar electromagnetic waves.
method Using statistical mechanics and Information Geometry, the paper defines a Fréchet barycentre and maximum entropy density for radar measurements.
result New tools for describing radar electromagnetic wave fluctuations, including a distance on covariance matrices.

In [16], a new family of vector-valued risk measures called multivariate expectiles is introduced. In this paper, we focus on the asymptotic behavior of these measures in a multivariate regular variations context. For models with equivalent tails, we propose an estimator of these multivariate asymptotic expectiles, in …

2017-04-24abs ↗pdf ↗

New metrics defined for full-rank correlation matrices, ensuring unique operations.

problem No suitable problem statement as the abstract does not describe a problem to be solved.
method New Riemannian metrics defined on full-rank correlation matrices, providing unique operations.
result Unique Riemannian logarithm and Fréchet mean defined for full-rank correlation matrices.

Proves FR-NGD optimally approximates evolutionary dynamics and continuous Bayesian inference.

problem Optimizing continuous time replicator equations and continuous Bayesian inference.
method Fisher-Rao natural gradient descent (FR-NGD) and its correspondence with evolutionary dynamics.
result FR-NGD optimally approximates continuous time replicator equations and continuous Bayesian inference.

This article follow the article {http://hal.archives-ouvertes.fr/hal-00361030/fr/} in which the author characterize the fact of being of finite volume for a convex projective surface. We show here that the moduli space βf(Σg,p)β_f(Σ_{g,p}) of the convex projective structure on the surface Σg,pΣ_{g,p} of genius gg with pp pun…

2009-10-30abs ↗pdf ↗

New formulas for geodesics on Stiefel and flag manifolds using trust-region method.

problem Computing geodesics and logarithms on Stiefel and flag manifolds.
method Closed-form geodesic formulas, trust-region solver, Fréchet derivatives.
result Efficient computation of geodesic distance and logarithm map.

FR-LUX optimizes portfolio management by learning cost-aware policies robust to market conditions.

problem Transaction costs and regime shifts cause failure in live trading portfolios.
method Integrates three ingredients: microstructure-consistent execution model, trade-space trust region, and explicit regime conditioning.
result Achieves top average Sharpe ratio, maintains flat cost-performance slope, and superior risk-return efficiency.

Many tasks in modern machine learning can be formulated as finding equilibria in \emph{sequential} games. In particular, two-player zero-sum sequential games, also known as minimax optimization, have received growing interest. It is tempting to apply gradient descent to solve minimax optimization given its popularity a…

2019-10-16abs ↗pdf ↗

This study provides an explicit expansion of KL divergence's gradient flow in Fisher-Rao geometry.

problem Sampling techniques struggle to traverse between modes in non-convex potential functions.
method Explicit expansion of KL divergence's gradient flow in Fisher-Rao geometry.
result The convergence rate to π is independent of the potential function.

The paper characterizes dynamic return and star-shaped risk measures via BSDEs.

problem Characterizing dynamic return and star-shaped risk measures.
method Characterization of star-shaped functionals and BSDEs.
result Existence of convex BSDEs with non-empty set of supersolutions.

Let GG be a compact connected simple Lie group and let $M=G^{\bb{C}}/P=G/K$ be a generalized flag manifold. In this article we focus on an important invariant of G/KG/K, the so called $\fr{t}$-root system $R_{\fr{t}}$, and we introduce the notion of symmetric $\fr{t}$-triples, that is triples of $\fr{t}$-roots $ξ, ζ, η…

2010-10-19abs ↗pdf ↗

The Delaunay tessellation of a locally finite subset of hyperbolic space is constructed using convex hulls in Euclidean space of one higher dimension. For finite and lattice-invariant sets it is proven to be a polyhedral decomposition, and versions (necessarily modified from the Euclidean setting) of the empty circumsp…

2013-08-22abs ↗pdf ↗

New methods classify convex lattice polygons for affine dimers.

problem Not all convex lattice polygons are characteristic polygons of affine dimers.
method General constructions and algorithm for finding affine dimers with prescribed polygons.
result All lattice triangles, generalised parallelograms, and polygons of genus at most two admit an affine dimer.

For an nn-dimensional real hyperbolic manifold MM, we calculate the Zariski tangent space of a character variety χ(π1(M),SL(n+1,R)),n>2χ(π_1(M),SL(n+1,\mathbb R)), n>2 at Fuchisan loci to show that the tangent space consists of cubic forms. Furthermore we prove the Weil's local rigidity theorem for uniforml hyperbolic lattices using rea…

2016-06-09abs ↗pdf ↗

A new method for estimating large-scale linear models with improved precision.

problem Estimating large-scale linear statistical models efficiently.
method Sequential Least-Squares Estimators with Fast Randomized Sketching (SLSE-FRS), integrating Sketch-and-Solve and Iterative-Sketching methods.
result SLSE-FRS produces high-precision estimators, outperforming state-of-the-art methods.

Study shows splitting schemes can approximate WFR flows faster than the exact flow.

problem Improving sampling efficiency in Wasserstein-Fisher-Rao gradient flows.
method Investigates operator splitting techniques to numerically approximate WFR flows.
result A judicious choice of step size and operator ordering can lead to faster convergence of split schemes to the target distribution.

Improved lattice field theory simulations with local-Autoregressive Conditional Normalizing Flow.

problem Efficiently sampling lattice field theories with computational challenges.
method Integrates locality into autoregressive conditional normalizing flows.
result Autocorrelation times improved by orders of magnitude for φ4φ^{4} theory on a 2D lattice.

Phishing as one of the most well-known cybercrime activities is a deception of online users to steal their personal or confidential information by impersonating a legitimate website. Several machine learning-based strategies have been proposed to detect phishing websites. These techniques are dependent on the features …

2019-03-13abs ↗pdf ↗

FR-Train improves fair and robust AI training by detecting and reducing poisoned data.

problem Training AI models that are fair and robust in the presence of data bias and poisoning.
method Mutual information-based adversarial training with an additional discriminator.
result FR-Train maintains fairness and accuracy even in the presence of poisoned data.

The paper finds incommensurable lattices in complex models of Baumslag-Solitar groups.

problem Locally finite 2-complexes and their automorphism groups contain incommensurable lattices.
method Constructing lattices in combinatorial models of Baumslag-Solitar groups and analyzing their properties.
result The constructed lattices are incommensurable and have specific properties like isomorphic Cayley graphs.

The paper establishes inequalities for convex curves and applies them to lattice point estimates.

problem Estimating the number of lattice points on convex curves.
method Developed comparison theorems for affine curves and used them to estimate areas and lattice points.
result Established inequalities for areas of inscribed triangles in terms of affine curvature and distance.

Consider an anchored bundle (E,ρ)(E,ρ), i.e. a vector bundle EME\to M equipped with a bundle map ρ ⁣:ETMρ\colon E \to TM covering the identity. M.~Kapranov showed in the context of Lie-Rinehard algebras that there exists an extension of this anchored bundle to an infinite rank universal free Lie algebroid FR(E)EFR(E)\supset E. We …

2019-04-11abs ↗pdf ↗

We study the motion of discrete interfaces driven by ferromagnetic interactions on the two-dimensional triangular lattice by coupling the Almgren, Taylor and Wang minimizing movements approach and a discrete-to-continuum analysis, as introduced by Braides, Gelli and Novaga in the pioneering case of the square lattice. …

2018-06-30abs ↗pdf ↗

In this paper we use techniques from convex projective geometry to produce many new examples of thin subgroups of lattices in special linear groups that are isomorphic to the fundamental groups of finite volume hyperbolic manifolds. More specifically, we show that for a large class of arithmetic lattices in SO(n,1) it …

2018-09-07abs ↗pdf ↗

We complete the quasi-isometric classification of irreducible lattices in semisimple Lie groups over nondiscrete locally compact fields of characteristic zero by showing that any quasi-isometry of a rank one S-arithmetic lattice in a semisimple Lie group over nondiscrete locally compact fields of characteristic zero is…

2005-04-11abs ↗pdf ↗

The paper disproves some implications in convex projective geometry.

problem Geometrical finiteness in round convex projective geometry.
method Construction of counterexamples and description of invariant domains.
result Existence of a counterexample with infinite Hilbert volume.

We study geodesics of the form γ(t)=π(exp(tX)exp(tY))γ(t)=π(\exp(tX)\exp(tY)), $X,Y\in \fr{g}=\operatorname{Lie}(G)$, in homogeneous spaces G/KG/K, where π:GG/Kπ:G\rightarrow G/K is the natural projection. These curves naturally generalise homogeneous geodesics, that is orbits of one-parameter subgroups of GG (i.e. γ(t)=π(exp(tX))γ(t)=π(\exp (tX)), $X\in …

2016-11-14abs ↗pdf ↗

We study cocompact lattices with dense projections in a product G1×G2G_1 \times G_2 of locally compact groups and show, under the assumption that each GiG_i is a closed subgroup of the automorphism group Aut(Ti)Aut(T_i) of a regular tree satisfying certain local transitivity conditions, that such a lattice is contained in only…

2013-05-21abs ↗pdf ↗

We show the local rigidity of complex hyperbolic lattices in classical Hermitian semisimple Lie groups, SU(np,p),Sp(2n+2,R),SO(2n+2),SO(2n,2)SU(np,p), Sp(2n+2,\mathbb R), SO^*(2n+2), SO(2n,2). This reproves or generalizes some results in \cite{GM, KKP, Klingler-inv, Pozzetti}.

2015-08-22abs ↗pdf ↗

Abstract framework for no-arbitrage concepts in topological vector lattices.

problem Generalization of no-arbitrage concepts in topological vector lattices.
method Imposing a structural condition on trading strategies and deriving abstract FTAP.
result NUPBR, NAA1_1, and NA1_1 may not be equivalent in general setting.

We study geodesics in generalized Wallach spaces which are expressed as orbits of products of three exponential terms. These are homogeneous spaces M=G/KM=G/K whose isotropy representation decomposes into a direct sum of three submodules m=m1m2m3\frak{m}=\frak{m}_1\oplus\frak{m}_2\oplus\frak{m}_3, satisfying the relations $[\fr…

2015-03-14abs ↗pdf ↗