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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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87175262349 · Jun 202019922001200920172026
48 results for ε-approximation lemma

The holonomic approximation lemma of Eliashberg and Mishachev is a powerful tool in the philosophy of the hh-principle. By carefully keeping track of the quantitative geometry behind the holonomic approximation process, we establish several refinements of this lemma. Gromov's idea from convex integration of working on…

2016-05-24abs ↗pdf ↗

It was pointed out to us that the proof of a crucial lemma (Lemma 5.3) in the paper is incorrect. Thus the approximation theorem (Theorem 0.1) for L^2 torsion of an amenable covering of a finite simplicial complex remains unproved. However, results and proofs of the first four sections (in particular, the approximation…

2000-08-28abs ↗pdf ↗

Proves theorem for Riemannian manifolds, extending previous work.

problem Proving Quantitative Fatou Theorem on Riemannian manifolds.
method Extending ε-approximation lemma to manifold setting.
result Proves Quantitative Fatou Theorem for Lipschitz domains on Riemannian manifolds.

This paper surveys various methods for dimensionality reduction and nearest neighbor search.

problem Efficiently reducing high-dimensional data to lower dimensions while preserving essential information.
method Linear and nonlinear random projections, including sparse random projections, random Fourier Features, and Random Kitchen Sinks.
result Various methods for dimensionality reduction and nearest neighbor search are explained and compared.

The proof of Brouwer's fixed-point theorem based on Sperner's lemma is often presented as an elementary combinatorial alternative to advanced proofs based on algebraic topology. The goal of this note is to show that: (i) the combinatorial proof of Sperner's Lemma can be considered as a cochain-level version, written in…

2009-06-29abs ↗pdf ↗

In this paper, we will study the existence problem of minmax minimal torus. We use classical conformal invariant geometric variational methods. We prove a theorem about the existence of minmax minimal torus in Theorem 5.1. Firstly we prove a strong uniformization result(Proposition 3.1) using method of [1]. Then we use…

2009-04-09abs ↗pdf ↗

The aim of this note is to extend the results in arXiv:1504.02043 to the case of approximate harmonic maps. More precisely, we will proved that the singular strata Sk(u)S^k(u) of an approximate harmonic map are k-rectifiable, and we will show effect bounds on the quantitative strata. In the process we will simplify many o…

2016-11-09abs ↗pdf ↗

Formulates Index III lemma and Rauch III theorem with applications.

problem Develops new mathematical theorems based on existing ones.
method Formulation of Index III lemma and Rauch III theorem based on Index I, II lemmas and Rauch I, II theorems.
result Presented Rauch's type theorem and volume comparison result as applications.

Tucker and Ky Fan's lemma are combinatorial analogs of the Borsuk-Ulam theorem (BUT). In 1996, Yu. A. Shashkin proved a version of Fan's lemma, which is a combinatorial analog of the odd mapping theorem (OMT). We consider generalizations of these lemmas for BUT-manifolds, i.e. for manifolds that satisfy BUT. Proofs rel…

2014-09-30abs ↗pdf ↗

Paper proves a discrete Schwarz-Pick lemma for generalized circle packings.

problem Comparing geometric quantities of circle packings with different boundary values.
method Combinatorial Calabi flows and maximum principle.
result Discrete Schwarz-Pick lemma proven for generalized circle packings.

The paper improves Zakalyukin's lemma for frontals and applies it to surface singularities.

problem Improving the conditions under which wave front germs imply map germs.
method Generalization of Zakalyukin's lemma for frontals and applications to surface singularities.
result The paper provides a more general version of Zakalyukin's lemma for map germs.

Meridian lemma extended to fully alternating links in thickened surfaces.

problem Extending Menasco's meridian lemma to fully alternating links in thickened surfaces.
method Developed a new meridian lemma for fully alternating links in thickened orientable surfaces of positive genus.
result The meridian lemma holds for fully alternating links in thickened surfaces.

The paper characterizes when the \partial \overline{\partial}-lemma holds for twistor spaces.

problem Characterizing the \partial \overline{\partial}-lemma for twistor spaces.
method Study Bott-Chern and Aeppli cohomologies of twistor spaces.
result Explicit computation of Dolbeault cohomology for flat torus twistor space.

Positive representations on surfaces have positive cross-ratios and satisfy a collar lemma.

problem Characterizing representations of surface groups with positive properties.
method Proving a collar lemma and showing positivity of cross-ratios for ΘΘ-positive representations.
result Closed subsets of representation varieties are characterized by ΘΘ-positive representations.

Enhanced Schwarz lemma for Hermitian manifolds with new curvature constraints.

problem Improving Schwarz lemma for holomorphic maps between Hermitian manifolds.
method Introducing new curvature constraints on source and target manifolds, controlling by holomorphic sectional curvature.
result Significant improvements on the Wu--Yau theorem and Schwarz lemma for Gauduchon connections.

The paper defines a stratification for Lie groupoids in a tame topology context.

problem Presenting a tame topology counterpart to canonical stratification of Lie groupoids.
method Using Shiota's isotopy lemma and approximation theorem, the paper defines a canonical Whitney stratification of definable Lie groupoids into invariant strata.
result A canonical Whitney stratification of the Lie groupoid into definable strata invariant under the groupoid action.

This paper studies the geometry of the group of all co-Hamiltonian diffeomorphisms of a compact cosymplectic manifold (M,ω,η)(M, ω, η). The fix-point theory for co-Hamiltonian diffeomorphisms is studied, and we use Arnold's conjecture to predict the exact minimum number of fix point that such a diffeomorphism must have (thi…

2019-12-29abs ↗pdf ↗

For the convenience of readers of the article {\em No-arbitrage pricing under systemic risk: accounting for cross-ownership} (Fischer, 2012, arXiv:1005.0768), a full proof of Lemma A.5 and a shorter proof of Lemma A.6 of that paper are provided.

2012-06-21abs ↗pdf ↗

The paper extends the Discrete Schwarz-Pick Lemma to circle packings with obtuse intersections and disjoint packings.

problem Proving the Discrete Schwarz-Pick Lemma for circle packings with various inversive distances.
method Using a variational principle for circle packings with inversive distances, the paper extends the lemma to a broader range of packings.
result The Discrete Schwarz-Pick Lemma holds for circle packings with inversive distances in (1,1](-1,1], provided an additional condition on triangle weights.

Develops a generalized version of Chung's Lemma for stochastic optimization methods.

problem Establishing asymptotic convergence rates for stochastic optimization methods under various step size rules.
method Generalized version of Chung's Lemma for a broader family of step size rules.
result Demonstrates tight non-asymptotic convergence rates for various stochastic methods.

We demonstrate new applications of the trace embedding lemma to the study of piecewise-linear surfaces and the detection of exotic phenomena in dimension four. We provide infinitely many pairs of homeomorphic 4-manifolds WW and WW' homotopy equivalent to S2S^2 which have smooth structures distinguished by several for…

2019-12-30abs ↗pdf ↗

The famous Švarc-Milnor Lemma says that a group GG acting properly and cocompactly via isometries on a length space XX is finitely generated and induces a quasi-isometry equivalence ggx0g\to g\cdot x_0 for any x0Xx_0\in X. We redefine the concept of coarseness so that the proof of the Lemma is automatic.

2006-03-21abs ↗pdf ↗

The L2L^2-\partial\overline\partial-Lemma is extended to complete Kähler manifolds with a gap in the spectrum.

problem Extending the L2L^2-\partial\overline\partial-Lemma to non-compact Kähler manifolds.
method Proving the L2L^2-\partial\overline\partial-Lemma on complete Kähler manifolds with a gap in the spectrum.
result The L2L^2-\partial\overline\partial-Lemma is generalized to complete Kähler manifolds.