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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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105209314418 · May 202619922001200920172026
48 results for sensing conditions

The paper improves conditions for unique recovery in homomorphic sensing of subspaces.

problem Unique recovery of points in a linear subspace from their images under linear maps.
method Tighter and simpler conditions for unique recovery in single and subspace arrangement cases, extending to noise stability.
result Conditions for unique recovery in homomorphic sensing are improved and unified.

We derive precise transformation formulas for synthetic lower Ricci bounds under time change. More precisely, for local Dirichlet forms we study how the curvature-dimension condition in the sense of Bakry-Emery will transform under time change. Similarly, for metric measure spaces we study how the curvature-dimension c…

2019-07-12abs ↗pdf ↗

Improved compressed sensing using a generator that learns from measurements.

problem Signal recovery accuracy in compressed sensing.
method Proposes a framework that uses measurement-conditional generative models to refine signal estimation.
result Uniformly superior performance with up to an order of magnitude reduction in reconstruction error.

We present sufficient conditions for the cohomology of a closed aspherical manifold to be proper Lipschitz in sense of Connes-Gromov-Moscovici [CGM]. The conditions are stated in terms of the Stone-Čech compactification of the universal cover of a manifold. We show that these conditions are formally weaker than the suf…

2002-05-15abs ↗pdf ↗

Improved convergence for overparameterized low-rank matrix sensing.

problem Overparameterized low-rank matrix sensing with unknown rank and ill-conditioning.
method ScaledGD(λλ) - preconditioned gradient descent method.
result ScaledGD(λλ) converges at a constant linear rate after a logarithmic number of iterations.

We present an information-theoretic framework for sequential adaptive compressed sensing, Info-Greedy Sensing, where measurements are chosen to maximize the extracted information conditioned on the previous measurements. We show that the widely used bisection approach is Info-Greedy for a family of kk-sparse signals b…

2014-07-02abs ↗pdf ↗

The present paper deals with the study of pseudo parallel (in the sense of Chaki and in the sense of Deszcz) contact CR-submanifolds with respect to Levi-Civita connection as well as semisymmetric metric connection of Kenmotsu manifolds and prove that these corresponding two classes are equivalent with a certain condit…

2017-06-28abs ↗pdf ↗

Study of Dirac-Witten operator on Lorentzian manifolds under dominant energy condition.

problem Detecting non-trivial homotopy groups in spaces of initial data under strict dominant energy condition.
method Use index theory and Lorentzian Hitchin's α-invariant to analyze Dirac-Witten operator.
result Kernel of Dirac-Witten operator is non-trivial only if fundamental group is virtually solvable of derived length at most 2.

Study surfaces with nonnegative curvature in spectral sense, proving inequalities and bounds.

problem Closed orientable surfaces with nonnegative curvature in spectral sense.
method Spectral condition and associated conformal metrics to prove inequalities and bounds.
result Isoperimetric inequalities, area growth theorems, and diameter bounds for surfaces.

Improved subgradient method tackles ill-conditioned composite optimization problems.

problem Slow convergence of subgradient method for composite optimization problems.
method Preconditioned subgradient method with Levenberg-Marquardt approach.
result Linear convergence rate for composite optimization problems under mild conditions.

Along a Ricci flow solution on a closed manifold, we show that if Ricci curvature is uniformly bounded from below, then a scalar curvature integral bound is enough to extend flow. Moreover, this integral bound condition is optimal in some sense.

2007-04-23abs ↗pdf ↗

In this paper, we study the problem of compressed sensing using binary measurement matrices and 1\ell_1-norm minimization (basis pursuit) as the recovery algorithm. We derive new upper and lower bounds on the number of measurements to achieve robust sparse recovery with binary matrices. We establish sufficient conditi…

2018-08-09abs ↗pdf ↗

AdaBoost improves binary classification in robust one-bit compressed sensing with adversarial errors.

problem Binary classification in robust one-bit compressed sensing with adversarial errors.
method AdaBoost and max-1\ell_1-margin-classifier approach, with convergence rates improved under certain feature conditions.
result Improved convergence rates and explanation for harmless interpolating adversarial noise.

Study shows Fredholmness of a Lorentzian Dirac operator on spacetimes.

problem Analyzing Fredholmness of a Lorentzian Dirac operator on spacetimes.
method Investigates Fredholmness of a (spatial) Γ-invariant Lorentzian Dirac operator under (anti) Atiyah-Patodi-Singer boundary conditions.
result Demonstrates Fredholmness of the operator in the von Neumann sense.

We prove that the "generic condition" used in singularity theorems of general relativity is generic in the space of Lorentzian metrics on a given manifold, in the sense that it is satisfied for all metrics in a residual set in the Whitney CkC^k-topology, for kk depending on the dimension of the manifold.

2017-01-25abs ↗pdf ↗

We study the value of information in sequential compressed sensing by characterizing the performance of sequential information guided sensing in practical scenarios when information is inaccurate. In particular, we assume the signal distribution is parameterized through Gaussian or Gaussian mixtures with estimated mean…

2015-09-01abs ↗pdf ↗

Given a complex of groups over a finite simplicial complex in the sense of Haefliger, we give conditions under which it is possible to build an EZ-structure in the sense of Farrell-Lafont for its fundamental group out of such structures for its local groups. As an application, we prove a combination theorem that yields…

2012-01-30abs ↗pdf ↗

The study establishes a curvature-dimension condition for discrete Markov chains.

problem Proving modified logarithmic Sobolev inequalities for discrete Markov chains.
method Identifying and proving a curvature-dimension inequality CDΥ(κ,)CD_Υ(κ,\infty), and showing its compatibility with diffusive settings.
result The CDΥCD_Υ condition preserves curvature bounds under tensorization and leads to Beckner inequalities.

Faster reconstruction of compressed signals using conditional GAN and NPGD.

problem Recovering compressed signals from measurements.
method Network-based projected gradient descent (NPGD) combined with measurement-conditional generative adversarial networks (GANs/BEGANs).
result Significant speed-up in reconstruction (up to 140-175 times faster).

A-DLISTA and VLISTA learn dictionaries and sparse representations under varying sensing matrices.

problem Learning dictionaries and sparse representations under varying sensing matrices.
method Augmented Dictionary Learning ISTA (A-DLISTA) and Variational Learning ISTA (VLISTA).
result VLISTA provides a probabilistic way to jointly learn the dictionary distribution and the reconstruction algorithm.

Stability conditions on K3 surfaces are linked to the masses of spherical objects.

problem Determining stability conditions on K3 surfaces.
method Using the masses of spherical objects and lax stability conditions associated to spherical bundles.
result Stability conditions on K3 surfaces are determined by the masses of spherical objects up to a natural C\mathbb{C}-action.

We present an introduction to boundary value problems for Dirac-type operators on complete Riemannian manifolds with compact boundary. We introduce a very general class of boundary conditions which contains local elliptic boundary conditions in the sense of Lopatinskij and Shapiro as well as the Atiyah-Patodi-Singer bo…

2013-07-11abs ↗pdf ↗

Study shows MDA's effectiveness even when more components are assumed than in actual data.

problem Classification error in overspecified Mixture Discriminant Analysis.
method Two-component Gaussian mixture model, EM algorithm, theoretical analysis of convergence and error rates.
result EM algorithm converges exponentially fast to Bayes risk with suitable initialization.

We prove Gray--Moser stability theorems for complementary pairs of forms of constant class defining symplectic pairs, contact-symplectic pairs and contact pairs. We also consider the case of contact-symplectic and contact-contact structures, in which the constant class condition on a one-form is replaced by the conditi…

2004-07-26abs ↗pdf ↗

Study improves distributed linear estimation under adversarial conditions.

problem Mean estimation of a random vector with adversarial measurements and asynchrony.
method Two-timescale ℓ1-minimization algorithm with tight convergence rates.
result Unified finite-time characterization of robustness, identifiability, and statistical efficiency.

We define an abstract notion of double Lie algebroid, which includes as particular cases: (1) the double Lie algebroid of a double Lie groupoid in the sense of the author, such as the iterated tangent bundle of an ordinary manifold, and various iterated tangent/cotangent constructions in symplectic and Poisson geometry…

2000-11-24abs ↗pdf ↗

State-space systems generate probabilistic dependencies between inputs and outputs.

problem Understanding probabilistic dependencies in state-space systems.
method Introducing a probabilistic framework and proving sufficient conditions for output existence and uniqueness.
result State-space systems can generate probabilistic dependencies, even without functional relations.

We extend the well-known result that any fW1,n(Ω,Rn)f \in W^{1,n}(Ω,\mathbb{R}^n), ΩRnΩ\subset \mathbb{R}^n with strictly positive Jacobian is actually continuous: it is also true for fractional Sobolev spaces Ws,ns(Ω)W^{s,\frac{n}{s}}(Ω) for any snn+1s \geq \frac{n}{n+1}, where the sign condition on the Jacobian is understood in a distr…

2019-05-17abs ↗pdf ↗

Recall that Federer-Fleming defined the notion of flat convergence of submanifolds of Euclidean space to solve the Plateau problem. Here we prove the upper semicontinuity of Neumann eigenvalues of the submanifolds when they converge in the flat sense without losing volume. With an additional condition on the boundaries…

2012-09-19abs ↗pdf ↗

In this paper, we study a special type of compact Hermitian manifolds that are Strominger Kähler-like, or SKL for short. This condition means that the Strominger connection (also known as Bismut connection) is Kähler-like, in the sense that its curvature tensor obeys all the symmetries of the curvature of a Kähler mani…

2019-08-14abs ↗pdf ↗