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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.

168,786 papers · 148 categories

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265177102 · May 202619922001200920172026
48 results for uniform rectifiability

Study proves existence of a specific type of flow in geometry.

problem Existence of canonical multi-phase free boundary Brakke flows.
method Global-in-time existence established using Brakke flow and uniform density ratio assumption.
result Existence of the flow with no positive mass on the free boundary for some short time.

This paper improves Reifenberg's theorem for almost calibrated sets, ensuring rectifiability with volume bounds.

problem Improving the rectifiability of sets that are close to subspaces under certain calibrations.
method Using ε-calibrations and positivity conditions, the paper shows that almost calibrated sets are rectifiable with volume bounds.
result Almost calibrated sets are rectifiable with uniform volume bounds.

We prove that the support of an m m dimensional rectifiable varifold with a uniform lower bound on the density and bounded generalized mean curvature can be covered Hm \mathscr{H}^{m} almost everywhere by a countable union of mm dimensional submanifolds of class C2 \mathcal{C}^{2} . We obtain this result using the …

2019-07-03abs ↗pdf ↗

The paper proves uniform Temple charts and applies them to null distance metrics.

problem Proving the existence of uniform Temple charts and their applications to null distance metrics.
method Constructing uniform Temple charts and estimating gradients of optical functions; applying these charts to study spacetime metrics.
result Proves (N,d^τ)(N, \hat{d}_τ) is a rectifiable metric space and applies a Lorentzian isometry theorem.

These series of notes serve as an introduction to some of both the classical and modern techniques in Reifenberg theory. At its heart, Reifenberg theory is about studying general sets or measures which can be, in one sense or another, approximated on all scales by well behaved spaces, typically just Euclidean space its…

2018-12-18abs ↗pdf ↗

We present the Tetrahedral Compactness Theorem which states that sequences of Riemannian manifolds with a uniform upper bound on volume and diameter that satisfy a uniform tetrahedral property have a subsequence which converges in the Gromov-Hausdorff sense to a countably Hm\mathcal{H}^m rectifiable metric space of the…

2012-10-17abs ↗pdf ↗

In this paper we study the regularity of stationary and minimizing harmonic maps f:B2(p)MNf:B_2(p)\subseteq M\to N between Riemannian manifolds. If $S^k(f)\equiv\{x\in M: \text{ no tangent map at $x$ is }k+1\text{-symmetric}\}$ is kthk^{th}-stratum of the singular set of ff, then it is well known that dimSkk\dim S^k\leq k, howeve…

2015-04-08abs ↗pdf ↗

The paper studies singular sets in Ricci flow limits, proving rectifiability and curvature bounds.

problem Understanding singular sets in Ricci flow limits.
method Stratification of singular sets, analysis of tangent flows, and geometric measure theory.
result Parabolic rectifiability of singular sets in certain dimensions and uniform curvature bounds.

For stationary harmonic maps between Riemannian manifolds, we provide a necessary and sufficient condition for the uniform interior and boundary gradient estimates in terms of the total energy of maps. We also show that if analytic target manifolds do not carry any harmonic S^2, then the singular sets of stationary map…

1999-05-01abs ↗pdf ↗

A space curve in a Euclidean 3-space E3\mathbb E^3 is called a rectifying curve if its position vector field always lies in its rectifying plane. This notion of rectifying curves was introduced by the author in [Amer. Math. Monthly {\bf 110} (2003), no. 2, 147-152]. In this present article, we introduce and study the n…

2016-07-28abs ↗pdf ↗

Study boundary behavior of limit interfaces in Riemannian manifolds without convexity assumptions.

problem Boundary behavior of limit interfaces in Riemannian manifolds.
method Proves limit-interface is a free boundary varifold, integer rectifiable up to boundary.
result No convexity assumption required; valid even when limit-interface clusters near boundary.

Harmonic maps to Euclidean buildings have rectifiable singular strata.

problem Understanding the structure of singular points for harmonic maps.
method Defining singular strata and proving rectifiability using the rectifiable Reifenberg program.
result Rectifiability of singular strata for harmonic maps into FF-connected complexes.

We prove (without using Federer's structure theorem) that a finite-mass flat chain over any coefficient group is rectifiable if and only if almost all of its 0-dimensional slices are rectifiable. This implies that every flat chain of finite mass and finite size is rectifiable. It also leads to a simple necessary and su…

1999-07-01abs ↗pdf ↗

The aim of this article is to study effective Reifenberg theorems for measures in a Hilbert or Banach space. For Hilbert spaces, we see all the results from Rn\mathbb{R}^n continue to hold with no additional restrictions. For a general Banach spaces we will see that the classical Reifenberg theorem holds, and that a we…

2018-06-04abs ↗pdf ↗

New methods for solving hydrodynamic-type equations using quasi-rectifiable Lie algebras.

problem Solving systems of hydrodynamic-type equations.
method Introducing and analyzing quasi-rectifiable Lie algebras and vector fields.
result New methods for solving hydrodynamic-type equations.

The paper generalizes rectifying and normal curves in Lorentzian n-space.

problem Characterizing and classifying gg-rectifying and gg-normal curves in Lorentzian n-space.
method Introducing a gg-position vector field and defining gg-rectifying and gg-normal curves based on this field.
result Comprehensive characterization and classification of gg-rectifying and gg-normal curves.

In this paper we investigate the performance of different types of rectified activation functions in convolutional neural network: standard rectified linear unit (ReLU), leaky rectified linear unit (Leaky ReLU), parametric rectified linear unit (PReLU) and a new randomized leaky rectified linear units (RReLU). We evalu…

2015-05-05abs ↗pdf ↗

Neural networks can approximate rectifiable measures with small error.

problem Approximating complex rectifiable measures using neural networks.
method Using ReLU neural networks to approximate (countably) m-rectifiable measures as push-forwards of the Lebesgue measure.
result The approximation error in terms of Wasserstein distance can be made arbitrarily small.

We show that C^1 hypersurfaces in the Heisenberg group are countably N-rectifiable. As a corollary, this shows that all C^1_H graphs over the xy-plane are countable N-rectifiable, showing the equivalence of this notion of rectifiability with that of Franchi, Serra Cassano and Serapioni for such surfaces.

2004-07-13abs ↗pdf ↗

In this paper, we introduce transformations of deep rectifier networks, enabling the conversion of deep rectifier networks into shallow rectifier networks. We subsequently prove that any rectifier net of any depth can be represented by a maximum of a number of functions that can be realized by a shallow network with a …

2017-03-30abs ↗pdf ↗

In Heisenberg groups, rectifiability is studied for subsets using C1,αC^{1,α}-regular surfaces.

problem Understanding rectifiability of subsets in Heisenberg groups.
method Introducing a new notion of rectifiability and proving conditions for rectifiability using tangent paraboloids.
result A sufficient condition for C1,αC^{1,α}-rectifiability of low-codimensional subsets in Heisenberg groups is the existence of suitable approximate tangent paraboloids.

The paper characterizes rectifying curves on smooth surfaces using isometries and Darboux frames.

problem Characterizing rectifying curves on smooth surfaces under isometries.
method Using Darboux frames and isometries to investigate rectifying curves.
result Find deviations of rectifying curves under isometries and analyze their properties.

In this paper, we introduce a new class of curves αcalled a f-rectifying curves, which its f-position vector defined by α_{f}(s)=\int f(s)T(s)ds always lie in the rectifying plane of α, where f is an integrable function and T is the speed curve of α. In particular case, when the function f=0 or constant, the class of f…

2018-10-21abs ↗pdf ↗

The paper explores rectified flows and their relation to optimal transport.

problem Understanding the connection between rectified flows and optimal transport.
method Investigates invariance properties, explicit constructions, and analysis of rectified flows in various settings.
result Rectified flows, when gradient constrained, do not generally solve optimal transport problems.

Rectified flows achieve optimal sample complexity for generating data.

problem Generating high-quality data samples efficiently.
method Rectified flows constrain transport trajectories to be linear, enabling efficient sampling.
result Achieve sample complexity of ildeO(ε2) ilde{O}(\varepsilon^{-2}), matching optimal rate for mean estimation.

We present examples of metric spaces that are not Riemannian manifolds nor dimensionally homogeneous that satisfy the Tetrahedral Property. In spite of that, Euclidean cones over metric spaces with small diameter do not satisfy this property. We extend Sormani's Tetrahedral Property to a less restrictive property and p…

2017-09-18abs ↗pdf ↗

The paper characterizes timelike rectifying curves in De Sitter 3-space.

problem Characterizing timelike rectifying curves in De Sitter 3-space.
method Defining timelike rectifying curves and conical surfaces, providing characterizations and results.
result Characterizations and results of timelike rectifying curves in De Sitter 3-space.

We extend rectified flow to infinite-dimensional Hilbert space.

problem Extending rectified flow to infinite-dimensional spaces.
method Established a rigorous functional formulation using the superposition principle for continuity equations.
result Demonstrated superior performance compared to existing models.

The rectified flow method is analyzed for its statistical properties.

problem Theoretical support for rectified flow methods is lacking.
method Empirical analysis of rectified flow's statistical properties using regression and density estimation.
result Convergence rates for rectified flow estimators are faster than for nonparametric regression and density estimation.

Rectifying curves on hypercones are geodesics, characterized in higher dimensions.

problem Characterizing rectifying curves in higher-dimensional spaces.
method Extending results from Chen (2017) to higher dimensions, using hypercones and hyperplanes.
result Rectifying curves on hypercones are geodesics, and these curves can be mapped to spherical curves in higher dimensions.

Study rectifying submanifolds with anti-torqued axis in Riemannian manifolds.

problem Characterize submanifolds with anti-torqued axis in Riemannian manifolds.
method Determine necessary and sufficient conditions for anti-torqued vector fields, characterize submanifolds, and derive rectifying submanifolds as warped products.
result Rectifying submanifolds with anti-torqued axis are warped products with specific warping functions.