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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.

168,695 papers · 148 categories

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4488132176 · Jun 202019922001200920172026
48 results for matrix rotations

Study optimizes estimation of orthogonal and rotation matrices from noisy data.

problem Estimating orthogonal and rotation matrices from noisy data.
method Iterative polar decomposition algorithm initialized by spectral methods.
result Algorithm achieves optimal error rate of $(1+o(1)) rac{σ^2 d(d-1)}{2np}$.

A new method for sparse PCA using orthogonal rotations and soft-thresholding.

problem Sparse PCA with a new basis using orthogonal rotations.
method Initialize with leading principal components, apply kimeskk imes k orthogonal rotation, and soft-threshold the rotated components.
result The proposed method is more stable and explains more variance compared to alternatives.

DFRot improves LLMs by reducing outlier and massive activation effects.

problem Reducing outlier and massive activation effects in rotated LLMs.
method Weighted loss function and orthogonal Procrustes transforms for rotation matrix refinement.
result DFRot achieves dual free (Outlier-Free and Massive Activation-Free) with significant improvements in perplexity.

Innovates rotation index for matrix pairs, solving group action problems.

problem Solving group actions problems, especially Nielsen realization and higher-rank Anosov actions.
method Rotation index and Milnor--Munkres--Novikov pairing applied to Z2\mathbb{Z}^2 group actions.
result Solved specific group action problems using new matrix pair invariant.

Predict missing movie ratings or graph embeddings with low rank matrices.

problem Predicting missing entries in a ratings matrix or graph embeddings with known linear relations.
method Low rank matrix completion approach applied to graph embeddings.
result Effective methods for predicting missing entries in matrices and graph embeddings.

Classifies SL(n) covariant matrix-valued valuations on Lp-spaces.

problem Classifying SL(n) covariant matrix-valued valuations on Lp-spaces.
method Established a complete classification for continuous and SL(n) covariant matrix-valued valuations on Lp(Rn,|x|2dx), eliminating matrix symmetry assumption.
result Unique characterization of such valuations by the moment matrix in n>2, rotation matrix in 2D.

Sparse principal component analysis (sparse PCA) aims at finding a sparse basis to improve the interpretability over the dense basis of PCA, meanwhile the sparse basis should cover the data subspace as much as possible. In contrast to most of existing work which deal with the problem by adding some sparsity penalties o…

2014-03-06abs ↗pdf ↗

The paper defines and calculates fourth fundamental form and i-th curvatures for hypersurfaces in 4D Euclidean space.

problem Calculating curvatures for hypersurfaces in 4D Euclidean space.
method Defining fourth fundamental form and i-th curvatures for hypersurfaces, calculating them on rotational hypersurface, and studying hypersurfaces satisfying a specific differential equation.
result Fourth fundamental form and i-th curvatures are defined and calculated for hypersurfaces in 4D Euclidean space.

RP-GFRFT unifies fractional order and rotation control for graph signals.

problem Lack of rotation-based spectral control in GFRFT and zero-angle degeneracy in AGFT.
method Rotation-parameterized graph fractional Fourier transform (RP-GFRFT) with degeneracy preserving rotation matrix.
result RP-GFRFT improves spectral filtering performance over existing methods.

Study connects covariance cleaning theory to information theory for heavy-tailed distributions.

problem Optimizing covariance matrices for heavy-tailed distributions using information theory.
method Minimizing Frobenius norm and information loss between true and estimated covariance matrices.
result Asymptotic regime of large matrices minimizes information loss for Student's t distributions.

Rotors were introduced in Graph Theory by W.Tutte. The concept was adapted to Knot Theory as a generalization of mutation by Anstee, Przytycki and Rolfsen in 1987. In this paper we show that Tristram-Levine signature is preserved by orientation-preserving rotations. Moreover, we show that any link invariant obtained fr…

2004-07-11abs ↗pdf ↗

Basis adaptation in Homogeneous Chaos spaces rely on a suitable rotation of the underlying Gaussian germ. Several rotations have been proposed in the literature resulting in adaptations with different convergence properties. In this paper we present a new adaptation mechanism that builds on compressive sensing algorith…

2018-01-06abs ↗pdf ↗

We investigate the problem of estimating a given real symmetric signal matrix C\textbf{C} from a noisy observation matrix M\textbf{M} in the limit of large dimension. We consider the case where the noisy measurement M\textbf{M} comes either from an arbitrary additive or multiplicative rotational invariant perturbati…

2015-02-24abs ↗pdf ↗

The paper develops a new algorithm for RBMs using dynamical mean-field theory.

problem Learning in Restricted Boltzmann Machines (RBMs) with complex dependencies.
method Dynamical mean-field theory applied to RBMs with rectangular coupling matrices drawn from a bi-rotation invariant ensemble.
result The algorithm converges globally under a stability criterion, with rates matching numerical simulations.

Whitening, or sphering, is a common preprocessing step in statistical analysis to transform random variables to orthogonality. However, due to rotational freedom there are infinitely many possible whitening procedures. Consequently, there is a diverse range of sphering methods in use, for example based on principal com…

2015-12-02abs ↗pdf ↗

We consider probabilistic PCA and related factor models from a Bayesian perspective. These models are in general not identifiable as the likelihood has a rotational symmetry. This gives rise to complicated posterior distributions with continuous subspaces of equal density and thus hinders efficiency of inference as wel…

2019-05-12abs ↗pdf ↗

The paper classifies rotational hypersurfaces in n-space using a modified Laplacian operator.

problem Classifying rotational hypersurfaces in n-dimensional Euclidean space.
method Investigating the Gauss map of rotational hypersurfaces with respect to the operator Ln3\mathbb{L}_{n-3}.
result Established a classification theorem connecting the matrix A\mathcal{A} and the Gauss map G\mathcal{G} through the equation Ln3G=AG\mathbb{L}_{n-3}\mathcal{G}=\mathcal{A}\mathcal{G}.

We study SU(2)SU(2) calorons, also known as periodic instantons, and consider invariance under isometries of S1×R3S^1\times\mathbb{R}^3 coupled with a non-spatial isometry called the rotation map. In particular, we investigate the fixed points under various cyclic symmetry groups. Our approach utilises a construction akin to…

2017-11-13abs ↗pdf ↗

OMD monitors stock market dynamics through matrix trajectories, revealing crisis patterns and sector rotations.

problem Understanding and predicting stock market dynamics during crises.
method Applying OMD to S&P 500 returns over three crises, analyzing distance matrices and their spectra.
result Market dynamics show coherent changes during crises, with sector-specific patterns and volatility clustering.

In (exploratory) factor analysis, the loading matrix is identified only up to orthogonal rotation. For identifiability, one thus often takes the loading matrix to be lower triangular with positive diagonal entries. In Bayesian inference, a standard practice is then to specify a prior under which the loadings are indepe…

2014-09-26abs ↗pdf ↗

OMD monitors stock market dynamics through matrix trajectories and reveals crisis patterns.

problem Understanding and predicting stock market crises and sector rotations.
method Applying OMD to S\&P 500 returns over three crises, analyzing distance matrices and their spectra.
result Market dynamics show coherent changes during crises, with distinct sector leadership.

A new algorithm computes elastic shape distances between curves efficiently.

problem Computing elastic shape distances between curves in high dimensions.
method Dynamic Programming for optimal diffeomorphisms and Kabsch-Umeyama algorithm for optimal rotation matrices.
result Efficient computation of elastic shape distances with improved efficiency for closed curves.

Bayes-optimal limits in PCA with structured noise are determined.

problem Analyzing statistical dependencies in measurement noise for high-dimensional inference.
method Study of spiked matrix model with low-order polynomial orthogonal noise, providing Bayes-optimal limits and proposing a novel AMP.
result A novel AMP algorithm reaches the information-theoretic limits for more general priors.

Gradient descent with noise converges to a unique optimum in nonconvex matrix factorization.

problem Gradient descent with noise converges to a unique optimum in nonconvex matrix factorization.
method A perturbed form of gradient descent with arbitrary initialization.
result Gradient descent with noise converges to a unique optimum.

New method constructs equivariant neural networks for arbitrary matrix groups.

problem Challenges in constructing equivariant neural networks for complex groups.
method Completely general algorithm for solving equivariant layers of matrix groups.
result Constructs multilayer perceptrons equivariant to multiple groups including O(1,3), O(5), Sp(n), and Rubik's cube group.

We propose a novel approach to addressing the vanishing (or exploding) gradient problem in deep neural networks. We construct a new architecture for deep neural networks where all layers (except the output layer) of the network are a combination of rotation, permutation, diagonal, and activation sublayers which are all…

2019-11-21abs ↗pdf ↗

We elaborate on the recent observation that evolution for twist knots simplifies when described in terms of triangular evolution matrix B{\cal B}, not just its eigenvalues ΛΛ, and provide a universal formula for B{\cal B}, applicable to arbitrary rectangular representation R=[rs]R=[r^s]. This expression is in terms of s…

2019-02-11abs ↗pdf ↗

The concepts of unitary evolution matrices and associative memory have boosted the field of Recurrent Neural Networks (RNN) to state-of-the-art performance in a variety of sequential tasks. However, RNN still have a limited capacity to manipulate long-term memory. To bypass this weakness the most successful application…

2017-10-26abs ↗pdf ↗

Spectral clustering performance depends on eigenvector fluctuations, shown to be Gaussian.

problem Predicting the performance of spectral clustering.
method General spike random matrix model and rotational invariance of noise.
result Fluctuations of eigenvector entries are Gaussian in large-dimensional regime.

Derives a sharp inequality for trace-free matrices with applications to hypersurfaces.

problem Classifying conformally flat hypersurfaces and characterizing rotational hypersurfaces.
method Derives a sharp inequality relating eigenvalues of trace-free matrices and applies it to hypersurfaces.
result New proof of the classification of conformally flat hypersurfaces and construction of a functional for rotational hypersurfaces.

Subsampled Randomized Hadamard Transform (SRHT), a popular random projection method that can efficiently project a dd-dimensional data into rr-dimensional space (rdr \ll d) in O(dlog(d))O(dlog(d)) time, has been widely used to address the challenge of high-dimensionality in machine learning. SRHT works by rotating the input …

2020-02-05abs ↗pdf ↗

In the framework of geometric quantization we extend the Bohr-Sommerfeld rules to a full quantization theory which resembles Heisenberg's matrix theory. This extension is possible because Bohr-Sommerfeld rules not only provide an orthogonal basis in the space of quantum states, but also give a lattice structure to this…

2012-07-05abs ↗pdf ↗

New method proves asymptotic normality for matrix sensing problems.

problem Proving asymptotic normality for matrix sensing under general convex losses.
method Riemannian geometry to handle degeneracy of the Hessian due to rotational symmetry.
result Proves n(φ0φ)DN(0,(H)1)\sqrt{n}(φ^0-φ^*)\xrightarrow{D}N(0,(H^*)^{-1}) as non o\infty.

A method for identifying joint and individual subspaces from multi-view data.

problem Unclear conditions for reliably identifying joint and individual subspaces from noisy, high-dimensional measurements.
method Rigorously quantifies conditions based on signal rank, principal angles, and noise levels. Characterizes spectrum perturbations of product of projection matrices.
result Estimates joint and individual subspaces more accurately than existing approaches in simulations and real-world applications.