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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.

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12243648 · Jun 202619922001200920172026
48 results for leaves

A compact Polish foliated space is considered. Part of this work studies coarsely quasi-isometric invariants of leaves in some residual saturated subset when the foliated space is transitive. In fact, we also use "equi-" versions of this kind of invariants, which means that the definition is satisfied with the same con…

2014-06-06abs ↗pdf ↗

We investigate the coarse homology of leaves in foliations of compact manifolds. This is motivated by the observation that the non-leaves constructed by Schweitzer and by Zeghib all have non-finitely generated coarse homology. This led us to ask whether the coarse homology of leaves in a compact manifold always has to …

2014-11-11abs ↗pdf ↗

Study shows conditions for continuity of foliated homeomorphisms action on space of leaves.

problem Conditions for continuity of foliated homeomorphisms action on space of leaves.
method Investigated sufficient conditions for continuity of the homomorphism ψ: H(X, Δ) → H(Y) induced by the action of foliated homeomorphisms on the space of leaves.
result Similar results hold for a more general class of partitions of locally compact Hausdorff spaces.

For a singular Riemannian foliation whose leaves are properly embedded, we show in the first part of this article the existence of global tubular neighbourhoods, and we develop a global description of the foliation as stratification by types of leaves. The second part deals with the further restriction to a foliation w…

2008-12-17abs ↗pdf ↗

We prove that for a generic 33-dimensional integrable rolling distribution of contact elements (excluding developable seed and isotropic developable leaves) isometric correspondence of leaves of a general nature (independent of the shape of the seed) requires the Bäcklund transformation.

2019-07-30abs ↗pdf ↗

Let f:M->M be a partially hyperbolic diffeomorphism such that all of its center leaves are compact. We prove that Sullivan's example of a circle foliation that has arbitrary long leaves cannot be the center foliation of f. This is proved by thorough study of the accessible boundaries of the center-stable and the center…

2011-04-28abs ↗pdf ↗

Investigates metric degeneracies on symplectic leaves using a generalized gradient flow.

problem Degeneracies in metrics on symplectic leaves of Poisson manifolds.
method Introduces the generalized double bracket (GDB) vector field to generalize gradient dynamics.
result Identifies admissible regions where the double bracket metric remains non-degenerate on symplectic leaves, enabling GDB as a gradient flow.

Optimizes hyperparameter tuning for models using approximate leave-one-out cross-validation.

problem Finding optimal hyperparameters for regularized models using approximate leave-one-out cross-validation.
method Derive efficient formulas for gradient and hessian of approximate leave-one-out cross-validation, apply second-order optimization.
result Demonstrates the effectiveness of the approach on real-world data sets.

We produce examples of codimension one foliations of the Euclidean and hyperbolic planes with bounded geometry which are topologically products, but for which leaves are non-recursively distorted. That is, the function which compares intrinsic distances in leaves with extrinsic distances in the ambient space grows fast…

2000-02-23abs ↗pdf ↗

We prove the Poisson geometric version of the Local Reeb Stability (from foliation theory) and of the Slice Theorem (from equivariant geometry). The result is also a generalization of Conn's linearization theorem from one-point leaves to arbitrary symplectic leaves (however, we do not make use of Conn's theorem).

2010-09-10abs ↗pdf ↗

We find computable criteria for stability of symplectic leaves of Poisson manifolds. Using Poisson geometry as an inspiration, we also give a general criterion for stability of leaves of Lie algebroids, including singular ones. This not only extends but also provides a new approach (and proofs) to the classical stabili…

2008-10-24abs ↗pdf ↗

ALO-CV approximates leave-one-out error in proportional regime.

problem Estimating generalization error in high-dimensional settings.
method Developed new analysis for ALO-CV, showed consistency under strong convexity.
result ALO-CV approximates leave-one-out error up to negligible error.

Paper accelerates conformal prediction by using approximate leave-one-out estimators.

problem Limited computational cost for conformal prediction.
method Incorporates approximate leave-one-out estimators to accelerate conformal prediction.
result ALO-based methods achieve comparable coverage and efficiency to exact methods but with significantly reduced runtime.

Let FF be a non-singular foliation on the plane with all leaves being closed subsets, H+(F)H^{+}(F) be the group of homeomorphisms of the plane which maps leaves onto leaves endowed with compact open topology, and H0+(F)H^{+}_{0}(F) be the identity path component of H+(F)H^{+}(F). The quotient $π_0 H^{+}(F) = H^{+}(F)/H^{+}_{0}…

2016-07-14abs ↗pdf ↗

Consider a singular Riemannian foliation (s.r.f for short) on a compact manifold. By successive blow-ups along the strata, we construct a regular Riemannian foliation on another compact Riemannian manifold and a desingularization map that projects leaves of the regular Riemannian foliation into leaves of the s.r.f. Thi…

2009-07-06abs ↗pdf ↗

The paper improves ALO for 1\ell_1-regularized models.

problem Estimating out-of-sample error for 1\ell_1-regularized models.
method Developed a novel theory for 1\ell_1-regularized problems, bounding ALO error.
result For 1\ell_1-regularized problems, ALO error goes to zero as p goes to infinity.

We prove that every closed, smooth nn-manifold XX admits a Riemannian metric together with a smooth, transversely oriented CMC foliation if and only if its Euler characteristic is zero, where by CMC foliation we mean a codimension-one, transversely oriented foliation with leaves of constant mean curvature and where t…

2014-04-07abs ↗pdf ↗

We consider Lorentzian manifolds with parallel light-like vector field V. Being parallel and light-like, the orthogonal complement of V induces a codimension one foliation. Assuming compactness of the leaves and non-negative Ricci curvature on the leaves it is known that the first Betti number is bounded by the dimensi…

2013-11-26abs ↗pdf ↗

The study finds dense orbits and absolute period leaves for complex flows.

problem Existence of dense orbits for real Rel flows on holomorphic 1-forms.
method Established a density criterion for mSL(2,R){ m SL}(2,\mathbb{R})-orbit closures, verified using explicit constructions.
result Found dense leaves and examples of absolute period foliation.

In this paper, we study a notion of hyperbolicity for hyperbolicity foliations with 1-dimensional parabolic leaves, namely the non-existence of holomorphic cylinders along the foliation - holomorphic maps from $\D^{n-1} \times \C$ to the manifold sending each $\{*\} \times \C$ to a leaf. We construct a tensor, that is …

2005-01-19abs ↗pdf ↗

Study foliations on Riemannian manifolds with specific vector fields, focusing on geometric properties.

problem Investigate foliations transverse to closed conformal vector fields on Riemannian manifolds.
method Analyze conditions for totally geodesic leaves and geometric constraints on foliations.
result Characterize totally geodesic foliations and classify minimal and constant mean curvature foliations.

Let XX be an (n+1)(n+1)-dimensional manifold, ΔΔ be a one-dimensional foliation on XX, and p:XX/Δp: X \to X / Δ be a quotient map. We will say that a leaf ωω of ΔΔ is special whenever the space of leaves X/ΔX / Δ is not Hausdorff at ωω. We present necessary and sufficient conditions for the map p:XX/Δp: X \to X / Δ to be a l…

2016-10-03abs ↗pdf ↗

The study classifies natural almost Hermitian structures on specific Lie groups.

problem Classifying natural almost Hermitian structures on conformally foliated Lie groups.
method Examining 4-dimensional Riemannian Lie groups with a 2-dimensional conformal foliation and minimal leaves, constructing new examples of multi-dimensional structures.
result Constructing several new multi-dimensional examples of almost Kähler, integrable, and Kähler structures.

The paper proves new comparison theorems for sub-Laplacian in foliations with minimal leaves.

problem Proving comparison theorems for sub-Laplacian in Riemannian foliations with minimal leaves.
method Using Riemannian foliations with minimal leaves, the paper proves comparison theorems for the sub-Laplacian.
result The comparison theorems yield a Bonnet-Myers type theorem, stochastic completeness, and Lipschitz regularization property for the sub-Riemannian semigroup.

Let F be a foliation of codimension 2 on a compact manifold with at least one non-compact leaf. We show that then F must contain uncountably many non-compact leaves. We prove the same statement for oriented p-dimensional foliations of arbitrary codimension if there exists a closed p form which evaluates positively on e…

2002-05-04abs ↗pdf ↗

Study shows how to deform foliated manifolds with flat leaves, leading to geometric characterization.

problem Deforming foliated manifolds with flat leaves while maintaining curvature bounds.
method Collapsing a manifold with a closed flat regular Riemannian foliation, keeping curvature uniformly bounded.
result For compact, simply connected manifolds, foliations are given by torus actions.

The paper studies homeotopy groups of leaf spaces for specific foliations.

problem Identifying homeotopy groups of leaf spaces for non-compact surfaces with non-compact leaves.
method Identifying homeotopy groups with automorphisms of graphs and showing induced homomorphisms.
result The induced homomorphism between homeotopy groups is either injective or has a kernel of Z_2.

Paper analyzes robust matrix completion with efficient nonconvex method and leave-one-out analysis.

problem Robust matrix completion with sparse noise.
method Alternates between projected gradient step for low-rank and thresholding step for sparse noise.
result Achieves linear convergence for general thresholding functions.