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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.

169,181 papers · 148 categories

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12.5%25.0%37.5%50.0% · May 199319922001200920182026
48 results for star-Ricci tensor

New tensor introduced for complex quadric hypersurfaces, no Hopf hypersurfaces found.

problem Characterizing real hypersurfaces in complex quadric using star-Ricci tensors.
method Introducing and analyzing star-Ricci tensors in real hypersurfaces of complex quadric.
result No Hopf hypersurfaces exist in Qm,m3Q^m, m\geq3, with certain star-Ricci tensors.

Among other results, a compact almost Kähler manifold is proved to be Kähler if the Ricci tensor is semi-negative and its length coincides with that of the star Ricci tensor or if the Ricci tensor is semi-positive and its first order covariant derivatives are Hermitian. Moreover, it is shown that there are no compact a…

2003-04-07abs ↗pdf ↗

We study the curvature of almost Hermitian manifolds and their special analogues via intrinsic torsion and representation theory. By deriving different forumlae for the skew-symmetric part of the star-Ricci curvature, we find that some of these contributions are dependent on the approach used, and for the almost Hermit…

2005-01-05abs ↗pdf ↗

The paper defines minimal norm tensors for curvature and divergence tensors, explaining Weyl and Cotten tensors.

problem Understanding curvature tensors and their minimal norm.
method Analyzing minimal norm tensors for third and fourth covariant tensors, including Riemannian curvature and divergence.
result Weyl tensor and Cotten tensor are identified as minimal norm tensors of Riemannian curvature and divergence tensors, respectively.

A new tree method for tensor data improves regression accuracy.

problem Efficiently modeling tensor data for regression problems.
method Scalar-output regression tree models for scalar-on-tensor problems, and tensor-on-tensor problems using additive tree ensemble approaches.
result The tensor-input tree (TT) method outperforms tensor-input GP models in efficiency and accuracy.

Curvature tensors can always be matched to a metric tensor under certain conditions.

problem Sectionally positive curvature tensors and their relationship to metric tensors.
method Existence and uniqueness of a metric tensor gabg_{ab} such that Rabcdgbd=gacλR_{abcd} g^{bd} = g_{ac} λ.
result A metric tensor gabg_{ab} can be found for sectionally positive curvature tensors, and it is unique up to a constant factor.

Paper optimizes tensor deflation for non-orthogonal signals.

problem Recovering low-rank signals from noisy tensors with correlated components.
method Developed an asymptotic analysis and optimized deflation procedure using random tensor theory.
result Proposed an efficient tensor deflation algorithm that optimizes a parameter introduced in the deflation mechanism.

Paper proposes a new method for exact recovery in robust tensor principal component analysis.

problem Exact recovery of low-rank and sparse components in tensors.
method Proposes a new method based on tensor-tensor product and t-SVD to solve a convex optimization problem.
result Exact recovery achieved in a deterministic fashion without randomness assumptions.

We introduce Bayesian multi-tensor factorization, a model that is the first Bayesian formulation for joint factorization of multiple matrices and tensors. The research problem generalizes the joint matrix-tensor factorization problem to arbitrary sets of tensors of any depth, including matrices, can be interpreted as u…

2014-12-15abs ↗pdf ↗

The paper tackles tensor factorization and completion from noisy data.

problem Sparse nonnegative tensor factorization and completion from partial and noisy observations.
method Minimizes the sum of maximum likelihood estimation and tensor 0\ell_0 norm with nonnegativity constraints.
result Error bounds and minimax lower bounds are established for the proposed model.

The paper examines properties of WW-curvature tensor in relativistic space-times.

problem Investigating the properties and implications of the WW-curvature tensor in relativistic space-times.
method Analyzing the semi-symmetry and divergence properties of the energy-momentum tensor in relation to the WW-curvature tensor.
result Space-times with specific properties of the WW-curvature tensor are classified as Einstein or Codazzi type.

Paper solves TRPCA problem for tensor data with new tensor nuclear norm.

problem Exact recovery of tensor low-rank and sparse components.
method Introduces tensor-tensor product and new tensor nuclear norm to solve TRPCA.
result The new tensor nuclear norm guarantees exact recovery of tensor data.

Proposes tensor Q-rank for better tensor rank recovery in complex data.

problem Improving tensor rank recovery for complex data with low sampling rate.
method Introduces tensor Q-rank and two selection methods for Q\mathbf{Q}, proposing VMTQN and MOTQN models.
result Demonstrates superior performance in tensor completion problems compared to TNN-based methods.

Tensorized Rademacher projections outperform Gaussian projections in reducing tensor dimensions.

problem Reducing the dimension of high-dimensional tensors for machine learning.
method Tensorized Rademacher random projections using Tensor Train decomposition.
result Tensorized Rademacher projections can replace Gaussian projections in tensor compression.

The paper shows how gradient flow on over-parametrized tensor decomposition behaves like deflation.

problem Understanding the training dynamics of gradient flow on tensor decomposition.
method Empirical observation and mathematical proof of gradient flow dynamics for orthogonally decomposable tensors.
result Gradient flow dynamics for orthogonally decomposable tensors follows a tensor deflation process, recovering all tensor components.

New method tackles non-smooth tensor data for better recovery.

problem Non-smooth changes in tensor data degrade traditional t-SVD methods.
method Learnable tensor nuclear norm, Alternating Proximal Multiplier Method (APMM), multi-objective tensor recovery framework.
result The proposed method effectively recovers tensor data with non-smooth changes.

Proposes FATTNN for tensor-on-tensor regression with improved prediction and reduced computation.

problem Tensor-on-tensor regression with complex tensor structures and nonlinear relationships.
method Integrates tensor factor models into deep neural networks to handle nonlinearity and reduce data dimensionality.
result Significant improvements in prediction accuracy and computational efficiency over traditional methods.

ScaledGD algorithm estimates low-rank tensors efficiently from corrupted data.

problem Estimating meaningful information from corrupted tensor data.
method Scaled gradient descent (ScaledGD) algorithm with tailored spectral initializations.
result ScaledGD achieves linear convergence at a constant rate independent of condition number.

Optimal low rank tensor recovery requires a minimum number of entries for accurate reconstruction.

problem Exact recovery of high order tensors of low rank from a subset of their entries.
method Riemannian optimization algorithm with initial value from a spectral method, leveraging tensor restricted isometry property and curvature of the manifold.
result Tensor of size nimesnimesimesnn imes n imes \cdots imes n of ranks (r,,r)(r,\cdots,r) can be reconstructed with high probability from O((rd+dnr)log(d))O((r^d+dnr)\log(d)) entries.

TRNN combines tensor geometry with neural network nonlinearity for HD data.

problem Modeling high-dimensional data with preserved tensor geometry and nonlinear interactions.
method Introduces TRNN that integrates tensor geometry and neural network nonlinearity.
result TRNN preserves tensor geometry while offering nonlinearity.

New methods solve tensor-on-tensor regression with unknown rank, revealing benefits of over-parameterization.

problem Connecting tensor responses to tensor covariates with unknown intrinsic rank.
method Riemannian gradient descent and Riemannian Gauss-Newton methods for tensor-on-tensor regression.
result Riemannian optimization methods converge linearly and quadratically to a statistically optimal estimate in rank over-parameterized settings.

The paper characterizes integrability of tensors on manifolds.

problem Analyzing integrability conditions for various tensor types on manifolds.
method Analytical and geometric characterizations of integrability for different tensor types, using Nijenhuis tensors.
result Integrability of tensors is equivalent to algebraic constancy coupled with vanishing of Nijenhuis-type tensors.

Introduces tensor bandits for multi-dimensional online decision making.

problem Optimal decision making in multi-dimensional online scenarios.
method Stochastic low-rank tensor bandits, tensor elimination, tensor epoch-greedy, tensor ensemble sampling.
result Tensor elimination and tensor epoch-greedy algorithms outperform existing methods.

Derdzinski and Shen's theorem on the restrictions posed by a Codazzi tensor on the Riemann tensor holds more generally when a Riemann-compatible tensor exists. Several properties are shown to remain valid in this broader setting. Riemann compatibility is equivalent to the Bianchi identity of the new "Codazzi deviation …

2012-04-05abs ↗pdf ↗

This paper studies how key tensor properties are inherited in subtensors of tensor train decompositions.

problem Theoretical development of property inheritance for subtensors in tensor train decompositions.
method Theoretical analysis of incoherence and condition number preservation, and tensor train rank preservation through fiber-wise sampling.
result Key tensor properties (incoherence and condition number) can be well preserved to subtensors formed via fiber-wise sampling.

Many problems can be formulated as recovering a low-rank tensor. Although an increasingly common task, tensor recovery remains a challenging problem because of the delicacy associated with the decomposition of higher order tensors. To overcome these difficulties, existing approaches often proceed by unfolding tensors i…

2014-05-07abs ↗pdf ↗

In the literature we see that after introducing a geometric structure by imposing some restrictions on Riemann-Christoffel curvature tensor, the same type structure given by imposing same restriction on other curvature tensors being studied. The main object of the present paper is to study the equivalency of various ge…

2013-01-30abs ↗pdf ↗

Improves group fairness in tensor completion by augmenting tensors with balanced entities.

problem Preventing discrimination in tensor decomposition based on social grounds.
method STAFF (Sparse Tensor Augmentation For Fairness) which augments tensors with balanced entities to mitigate imbalance and bias.
result Consistently shows the best trade-off between completion error and group fairness, reducing errors by 36% and 59% respectively.

JULIA combines multi-linear and nonlinear models for tensor completion.

problem Complex patterns in real-world tensors require a unified model.
method JULIA unifies multi-linear and nonlinear models with flexible component assignment and efficient alternating optimization.
result JULIA outperforms existing methods in large-scale tensor completion.