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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.

168,657 papers · 148 categories

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255075100 · May 202619922001200920172026
48 results for subspace refinement

Paper finds necessary condition for logarithmic Minkowski problem in higher dimensions.

problem Logarithmic Minkowski problem in higher dimensions.
method Established a necessary condition through generalization and refinement of previous work.
result Generalizes and refines necessary condition for logarithmic Minkowski problem.

This paper improves Koopman operator approximations by pruning subspaces in RKHS.

problem Improving predictive accuracy of Koopman operator approximations.
method Computes principal angles and vectors in RKHS to prune subspaces.
result Validated approach enhances Koopman operator approximations for large datasets.

CobBO optimizes expensive functions in high dimensions by using a two-stage kernel approach.

problem Bayesian optimization struggles in high dimensions due to computational inefficiency.
method Coordinate backoff Bayesian Optimization with two-stage kernels.
result CobBO finds solutions comparable to or better than other methods in high dimensions.

In this paper, we study Conley theory in Hilbert spaces and make some refinement of the construction of the stable Conley index developed by Gȩba, Izydorek, and Pruszko. For instance, we allow subspaces other than invariant subspaces in the the construction. As a main result, we show that the resulting stable Conley in…

2014-02-07abs ↗pdf ↗

Stability result for nearly isometric subspaces and Finsler surfaces.

problem Stability of normed spaces and Finsler surfaces under near-isometric conditions.
method Refined topological argument and explicit quantification using Banach-Mazur distance.
result A 2-dimensional surface with near-monochromatic Finsler metric is approximately Riemannian.

We introduce the bilinear bandit problem with low-rank structure in which an action takes the form of a pair of arms from two different entity types, and the reward is a bilinear function of the known feature vectors of the arms. The unknown in the problem is a d1d_1 by d2d_2 matrix Θ\mathbfΘ^* that defines the reward…

2019-01-08abs ↗pdf ↗

Improved Nyström approximation for kernel quadrature with theoretical guarantees.

problem Efficiently approximating positive definite kernels for large datasets.
method Refined sampling and subspace selection in Nyström approximation.
result Novel theoretical guarantees for non-i.i.d. landmark points in kernel quadrature.

Enhances SDR via Hellinger correlation for better data dependency understanding.

problem Improving sufficient dimension reduction in single-index models.
method Developed a new method using Hellinger correlation for detecting the dimension reduction subspace.
result Significantly enhances and outperforms existing SDR methods through deeper data dependency understanding.

The first order behavior of multivariate heavy-tailed random vectors above large radial thresholds is ruled by a limit measure in a regular variation framework. For a high dimensional vector, a reasonable assumption is that the support of this measure is concentrated on a lower dimensional subspace, meaning that certai…

2019-06-26abs ↗pdf ↗

With the scale of data growing every day, reducing the dimensionality (a.k.a. sketching) of high-dimensional data has emerged as a task of paramount importance. Relevant issues to address in this context include the sheer volume of data that may consist of categorical samples, the typically streaming format of acquisit…

2016-09-27abs ↗pdf ↗

Paper proposes CLAIR for efficient LLM fine-tuning across clients.

problem Fine-tuning large language models (LLMs) efficiently and collaboratively.
method Federated LoRA fine-tuning with Collaborative Low-rank Alignment and Identifiable Recovery (CLAIR).
result CLAIR achieves better performance and contamination detection compared to local fine-tuning.

Proposes HeteroJIVE for joint subspace estimation in multi-view data with statistical and structural heterogeneity.

problem Joint subspace estimation in multi-view data with varying statistical and structural heterogeneity.
method HeteroJIVE: A weighted two-stage spectral algorithm addressing statistical and structural heterogeneity.
result HeteroJIVE achieves the O(K1/2)O(K^{-1/2}) rate without iterative refinement, validating the oracle-optimal weighting scheme.

New algorithm for linear bandits tackles Optimal Transport problems.

problem Optimal Transport problems not covered by traditional linear bandits.
method Embed actions into a Hilbertian subspace, penalize optimism, use least-squares estimation.
result Achieves same regret bounds as OFUL but interpolates between ildeO(T) ilde{\mathcal O}(\sqrt{T}) and O(T){\mathcal O}(T).

Sliced inverse regression (SIR) is a pioneer tool for supervised dimension reduction. It identifies the effective dimension reduction space, the subspace of significant factors with intrinsic lower dimensionality. In this paper, we propose to refine the SIR algorithm through an overlapping slicing scheme. The new algor…

2018-06-23abs ↗pdf ↗

We introduce a new method for sparse principal component analysis, based on the aggregation of eigenvector information from carefully-selected axis-aligned random projections of the sample covariance matrix. Unlike most alternative approaches, our algorithm is non-iterative, so is not vulnerable to a bad choice of init…

2017-12-15abs ↗pdf ↗

The paper studies posets from decompositions in symmetric monoidal categories.

problem Understanding posets from decompositions in symmetric monoidal categories.
method Defining decompositions and partial decompositions, complexes of frames, partial bases, and ordered versions.
result Unified approach to combinatorics and homotopy type of posets and complexes.

Paper introduces G-LowTESTR for efficient tensor bandits.

problem Efficient decision-making in multi-dimensional data with non-linear reward functions.
method Generalized low-rank tensor contextual bandits model and G-LowTESTR algorithm.
result G-LowTESTR achieves superior regret bound compared to vectorization and matricization methods.

Study Sp(n)Sp(n)-orbits in complex and ΣΣ-complex subspaces of Hermitian quaternionic vector spaces.

problem Characterize Sp(n)Sp(n)-orbits in Grassmannians of complex and ΣΣ-complex subspaces.
method Decompose subspaces into 4-dimensional complex addends and 2-dimensional totally complex subspace. Use properties of isoclinic subspaces and principal angles.
result Determine full set of invariants for Sp(n)Sp(n)-orbits in GrR(2k,4n)Gr^\R(2k,4n).

In subspace clustering, a group of data points belonging to a union of subspaces are assigned membership to their respective subspaces. This paper presents a new approach dubbed Innovation Pursuit (iPursuit) to the problem of subspace clustering using a new geometrical idea whereby subspaces are identified based on the…

2015-12-02abs ↗pdf ↗

Paper shows affine constraint is unnecessary for high-dimensional data.

problem The necessity of an affine constraint in affine subspace clustering.
method Theoretical and empirical analysis of conditions for correctness of affine subspace clustering methods.
result Affine constraint has negligible effect on clustering performance for high-dimensional data.

A low-rank transformation learning framework for subspace clustering and classification is here proposed. Many high-dimensional data, such as face images and motion sequences, approximately lie in a union of low-dimensional subspaces. The corresponding subspace clustering problem has been extensively studied in the lit…

2013-09-09abs ↗pdf ↗

This paper investigates the generalization of Principal Component Analysis (PCA) to Riemannian manifolds. We first propose a new and general type of family of subspaces in manifolds that we call barycentric subspaces. They are implicitly defined as the locus of points which are weighted means of k+1k+1 reference points.…

2016-07-11abs ↗pdf ↗

Flow Matching models help generative models stay within the subspace of real data.

problem How do generative models stay within the subspace of real data?
method Flow Matching models using a learned velocity field to transform a simple prior into a complex target distribution.
result Generated samples memorize real data points and represent the sample data subspace exactly.

In this letter, we consider two sets of observations defined as subspace signals embedded in noise and we wish to analyze the distance between these two subspaces. The latter entails evaluating the angles between the subspaces, an issue reminiscent of the well-known Procrustes problem. A Bayesian approach is investigat…

2013-10-01abs ↗pdf ↗

Give deterministic necessary and sufficient conditions to guarantee that if a subspace fits certain partially observed data from a union of subspaces, it is because such data really lies in a subspace. Furthermore, Give deterministic necessary and sufficient conditions to guarantee that if a subspace fits certain parti…

2014-08-24abs ↗pdf ↗

New inequality for refined knot invariants in a specific space.

problem General adjunction inequality for refined ss-invariants does not hold.
method Introduced an adjunction inequality for a specific spatial refinement in kCP2k\overline{\mathbb{CP}^2}.
result An adjunction inequality holds for the ss-version of the Sq1Sq^1-refinement in kCP2k\overline{\mathbb{CP}^2}.

An elliptic theory is constructed for operators acting in subspaces defined via odd pseudodifferential projections. Subspaces of this type arise as Calderon subspaces for first order elliptic differential operators on manifolds with boundary, or as spectral subspaces for self-adjoint elliptic differential operators of …

1999-07-07abs ↗pdf ↗

Stochastic Sparse Subspace Clustering improves subspace clustering by reducing over-segmentation through dropout.

problem Over-segmentation in subspace clustering.
method Introducing dropout regularization to enforce denser connections between points from the same subspace.
result Stochastic Sparse Subspace Clustering effectively handles large datasets and reduces over-segmentation.

Sparse subspace clustering (SSC) is an elegant approach for unsupervised segmentation if the data points of each cluster are located in linear subspaces. This model applies, for instance, in motion segmentation if some restrictions on the camera model hold. SSC requires that problems based on the l1l_1-norm are solved …

2016-09-16abs ↗pdf ↗

This paper considers the problem of robust subspace recovery: given a set of NN points in RD\mathbb{R}^D, if many lie in a dd-dimensional subspace, then can we recover the underlying subspace? We show that Tyler's M-estimator can be used to recover the underlying subspace, if the percentage of the inliers is larger t…

2012-06-07abs ↗pdf ↗

Fast robust subspace tracking in sparse data-dependent noise with near-optimal delay.

problem Robustly tracking time-varying subspaces in the presence of sparse outliers.
method Introduces a fast mini-batch robust ST solution under mild assumptions.
result Provably correct subspace tracking with near-optimal delay and same time complexity as simple PCA.