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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.

169,341 papers · 148 categories

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1223 · May 201619922001200920182026
48 results for Sierpiński compacta

The paper examines properties of self-affine Sierpiński sponges using metric invariants.

problem Investigating properties of self-affine Sierpiński sponges using metric invariants.
method Examined through maximal power law property and perfectly disconnectedness.
result Characterized self-affine Sierpiński sponges by their metric properties.

It is shown that if MM is a strongly causal free of naked singularities space-time, then its causal structure is completely characterized by a partial order in the space of skies defined by means of a class non-negative Legendrian isotopies. It is also proved that such partial order is determined by the class of futur…

2014-11-06abs ↗pdf ↗

We rephrase Gromov's definition of Markov compacta, introduce a subclass of Markov compacta defined by one building block and study cohomological dimensions of these compacta. We show that for a Markov compactum XX, $\dim_{\Z_{(p)}}X=\dim_{\Q}X$ for all but finitely many primes pp where Z(p)\Z_{(p)} is the localization…

2006-11-01abs ↗pdf ↗

This paper analyzes error in SKI for Gaussian Processes, providing conditions for linear time inference.

problem Lack of rigorous theoretical error analysis for SKI.
method Proved error bounds for SKI Gram matrix, examined error effects, provided practical guidelines.
result Identified two dimensionality regimes for SKI's scalability-accuracy trade-offs.

The study describes how topological properties of Markov compacta can be inferred from their diagrammatic structures.

problem Detecting topological properties of Markov compacta using combinatorial diagrams.
method Developed a formalism to describe Markov compacta with finite sets of diagrams, linking topological properties to combinatorial structures.
result Topological properties of Markov compacta can be inferred from the combinatorial properties of their diagrams.

The paper improves a result about 2D ANR spaces by proving full-valuedness for certain metric compacta.

problem Proving full-valuedness for compact metric spaces, especially two-dimensional ones.
method Introducing and analyzing the homological dimension dGd_G for metric compacta.
result Two-dimensional lc^2 metric compacta are dimensionally full-valued.

Efficiently maps indoor magnetic fields with SKI and D-SKI.

problem Computing large-scale magnetic field maps in indoor environments.
method Structured kernel interpolation (SKI) with derivatives (D-SKI) for Gaussian process regression.
result Achieves better accuracy and faster computation than state-of-the-art methods.

Fine shape of local compacta represented by ordinary maps.

problem Representing fine shape of local compacta.
method Constructing a space X|X| for each local compactum XX such that fine shape classes correspond to homotopy classes of maps to X|X|.
result Fine shape classes from any locally compact metrizable space YY to XX bijectively correspond to homotopy classes of maps from YY to X|X|.

SoftKI combines SKI and variational methods for scalable GP regression.

problem Scalable Gaussian Process regression on high-dimensional datasets.
method SoftKI approximates kernel via softmax interpolation from a smaller number of learned points.
result SoftKI is competitive with other approximated GP methods for modest data dimensions.

We present some results on n-dimensional compacta lying in n-dimensional products of compacta, in particular, in products of n 1-dimensional compacta. Most of our basic results are proven under the assumption that the compacta X admit essential maps into the n-sphere. The results of the present paper may be viewed as a…

2007-12-20abs ↗pdf ↗

The paper proposes calibration to improve algorithm performance using machine learning predictions.

problem Improving real-world performance of online algorithms with machine learning predictions.
method Calibration as a tool to bridge the gap between prediction uncertainty and algorithm design.
result Calibrated advice leads to more effective guidance in high-variance settings and significant performance improvements in real-world data.

SKI speeds up Toeplitz Neural Networks by avoiding explicit decay bias and using frequency response.

problem Efficiently compute and update Toeplitz matrices in neural networks.
method Sparse plus low-rank decomposition, asymmetric SKI, frequency response modeling.
result Achieved significant speedup with minimal performance loss.

New technique speeds up Gaussian process inference for large datasets.

problem Efficient inference for Gaussian processes in high dimensions.
method Product Kernel Interpolation (SKI) with iterative methods exploiting matrix-vector multiplications.
result Linear runtime with dimension for SKI, state-of-the-art asymptotic complexity for multi-task GPs.

New Coxeter groups yield n-dimensional Sierpiński boundaries.

problem Creating Coxeter groups with specific boundary shapes.
method Defined a class of right-angled Coxeter systems and provided conditions for their boundaries.
result Coxeter groups produce boundaries homeomorphic to n-dimensional Sierpiński compacta.

Spaces are classified as almost homology n-manifolds if their homology groups are trivial for all but the last dimension.

problem Classifying spaces as almost homology n-manifolds.
method Providing a necessary and sufficient condition for locally compact homogeneous ANR-spaces or strongly locally homogeneous ANR-spaces to be almost homology n-manifolds.
result Spaces are classified as almost homology n-manifolds based on their homology groups.

The paper confirms properties of homogeneous ANR compacta and their homological similarities.

problem Properties of homogeneous ANR compacta and their homological similarities.
method Analyzes local homological properties and cyclicity of homogeneous ANR compacta.
result Homogeneous ANR compacta have similar local homological properties to closed balls and their boundaries.

The paper explores homological dimensions and dimensional full-valuedness in metric compacta.

problem Investigating homological dimensions and dimensional full-valuedness in metric compacta.
method Comparing Čech and Steenrod homology dimensions, proving dimensional full-valuedness for specific conditions.
result Two-dimensional metric compacta with specific properties satisfy dimensionally full-valuedness.

Compacta X and Y are said to admit a stable intersection in R^n if there are maps f : X -> R^n and g : Y -> R^n such that for every sufficiently close continuous approximations f' : X -> R^n and g' : Y -> R^n of f and g we have f'(X)\cap g'(Y)\neq\emptyset. The well-known conjecture asserting that X and Y do not admit …

2013-10-08abs ↗pdf ↗

Let L be a countable and locally finite CW complex. Suppose that the class of all metrizable compacta of extension dimension not greater than L contains a universal element which is an absolute extensor in dimension L. Our main result shows that L is quasi-finite.

2004-05-12abs ↗pdf ↗

Cencelj and Dranishnikov showed that for certain nilpotent groups GG, K(Gab,1)AE(X)K(G_{ab},1) \in \text{AE}(X) is equivalent to K(G,1)AE(X)K(G,1) \in \text{AE}(X) for any compacta XX (here GabG_{ab} is the abelianization of GG). We examine the same problem for solvable groups. We also give an elementary proof of this fact for any nilpo…

2005-07-18abs ↗pdf ↗

We give a short answer to the question in the title: {\em dendrits}. Precisely we show that the CC^{\ast}-algebra C(X)C(X) of all complex-valued continuous functions on a compactum XX is projective in the category C1{\mathcal C}^{1} of all (not necessarily commutative) unital CC^{\ast}-algebras if and only if XX is a…

2009-02-17abs ↗pdf ↗

Smooth knots can be embedded into a specific Menger continuum.

problem Embedding smooth knots into a specific type of continuum.
method Explicit construction using cubical models and self-similarity of the Menger continuum.
result Every smooth knot can be isotoped into the Menger continuum.

The set N of all null geodesics of a globally hyperbolic (d+1)-dimensional spacetime (M,g) is naturally a smooth (2d-1)-dimensional contact manifold. The sky of an event is the subset of N defined by all null geodesics through that event, and is an embedded Legendrian submanifold of N diffeomorphic to a (d-1)-dimension…

2002-10-11abs ↗pdf ↗

It is an open question (Pawlikowski) whether every finitely generated group can be realized as a fundamental group of a compact metric space. In this paper we prove that any countable group can be realized as the fundamental group of a compact subspace of four dimensional Euclidean space. According to theorems of Shela…

2008-10-20abs ↗pdf ↗

The paper uses polyhedral expansions to capture the shape of compact metric spaces.

problem Capturing the shape of compact metric spaces using finite approximations.
method Inverse sequences of polyhedra based on finite approximations of a compact metric space.
result Proves the General Principle and computes inverse persistent homology groups.

Steenrod homotopy theory is a framework for doing algebraic topology on general spaces in terms of algebraic topology of polyhedra; from another viewpoint, it studies the topology of the lim^1 functor (for inverse sequences of groups). This paper is primarily concerned with the case of compacta, in which Steenrod homot…

2008-12-08abs ↗pdf ↗