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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.

168,742 papers · 148 categories

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63125188250 · May 202619922001200920172026
48 results for direction concentration

The study characterizes heat flow and concentration on directed graphs with a lower Ricci curvature bound.

problem Understanding heat flow and concentration on directed graphs with a specific curvature bound.
method Characterization via gradient estimate and transportation inequality for the heat semigroup.
result Concentration of measure inequality for directed graphs with positive Ricci curvature.

Study proves uniqueness of Yang-Mills field tangent cones in arbitrary dimensions.

problem Proving uniqueness of Yang-Mills field tangent cones.
method Log-epiperimetric inequality, Luckhaus type lemma, and curvature concentration exclusion.
result Uniqueness of tangent cones for Yang-Mills fields in arbitrary dimensions.

We consider a priori generalization bounds developed in terms of cross-validation estimates and the stability of learners. In particular, we first derive an exponential Efron-Stein type tail inequality for the concentration of a general function of n independent random variables. Next, under some reasonable notion of s…

2017-06-19abs ↗pdf ↗

Paper develops bounds for stochastic approximation with averaging.

problem Establish high-probability bounds for averaged stochastic approximation.
method Develops a general framework for non-asymptotic concentration bounds.
result Derives sharp bounds for averaged iterates and tightens existing results.

A new distance metric for vMF distributions simplifies spherical data analysis.

problem Intractability of normalization constants and lack of suitable geometric metrics for comparing vMF distributions.
method Proposes a Wasserstein-like distance that decomposes vMF distribution discrepancies into angular and concentration components.
result The proposed distance metric induces a latent geometric structure on the space of non-degenerate vMF distributions.

Phase segregation, the process by which the components of a binary mixture spontaneously separate, is a key process in the evolution and design of many chemical, mechanical, and biological systems. In this work, we present a data-driven approach for the learning, modeling, and prediction of phase segregation. A direct …

2018-03-23abs ↗pdf ↗

Proves existence of solutions with concentrated energy in 2+1 spacetime.

problem Existence of solutions with concentrated energy in 2+1 spacetime.
method Direct treatment of 2+1 Einstein equations, novel scaling, Klainerman-Sobolev inequality.
result Uniform finite-time existence of solutions with positive incoming H1H^1 energy.

Constructs ε-splitting maps for geodesic balls with non-negative Ricci curvature.

problem Constructing ε-splitting maps for geodesic balls with non-negative Ricci curvature.
method Induction and stratified almost Gou-Gu Theorem for finding directional points; error estimates for projections.
result Constructs εε-splitting maps on concentric geodesic balls with uniformly small radius.

The paper solves a specific type of Ambrosetti-Prodi problem with solutions having clustering concentration layers.

problem Solving a particular Ambrosetti-Prodi type problem with solutions having concentration layers.
method Using a matrix function and eigenfunction of a related operator, the paper constructs solutions with concentration layers directed along a closed curve.
result Proves the existence of a sequence of solutions with clustering concentration layers directed along a closed curve.

ZDP detects drift in large language models without labels, proving key theorems and metrics.

problem Detecting drift in large language models without task labels or output evaluations.
method Zero-Direction Probing (ZDP) framework based on null directions of transformer activations, proving theoretical guarantees.
result Proves the Variance--Leak Theorem, Fisher Null-Conservation, Rank--Leak bound, and logarithmic-regret guarantee.

Proposes a method to estimate sparse Gaussian graphical models with hidden clustering structure.

problem Modeling statistical relationships between variables with sparsity and clustering.
method Two-phase algorithm using sGS-ADMM for initial point and pALM for solution.
result Demonstrates good performance and efficiency of the proposed model and algorithm on synthetic and real data.

ConMeZO speeds up zeroth-order optimization for large language models.

problem Slow convergence in high-dimensional parameter spaces of large language models.
method Adaptive directional sampling in a cone centered around a momentum estimate.
result Achieves the same convergence rate as MeZO but up to 2X faster.

The Langevin Algorithm's stationary distribution is shown to be sub-exponential or sub-Gaussian under certain conditions.

problem Understanding the properties of the Langevin Algorithm's stationary distribution.
method Analysis using a rotation-invariant moment generating function (Bessel function) to study the stationary dynamics of the Langevin Algorithm.
result Concentration results for the Langevin Algorithm's stationary distribution πηπ_η are established, showing it is sub-exponential or sub-Gaussian under convex or strongly convex potential conditions.

LASER compresses recursive model activations by exploiting their low-dimensional structure.

problem Understanding and optimizing the geometric structure of recursive reasoning trajectories.
method Dynamic low-rank basis tracking via matrix-free subspace tracking with a fidelity-triggered reset mechanism.
result Recursive activations occupy a linear, low-dimensional subspace that can be compressed efficiently.

We analyze a family of methods for statistical causal inference from sample under the so-called Additive Noise Model. While most work on the subject has concentrated on establishing the soundness of the Additive Noise Model, the statistical consistency of the resulting inference methods has received little attention. W…

2013-12-19abs ↗pdf ↗

High-probability bound for distributed stochastic approximation tracking error.

problem Analyzing the convergence of distributed stochastic approximation schemes.
method Analysis using ODE approach to stochastic approximation.
result High probability bound for tracking error between iterates and limiting differential equation.

A new dimension reduction method based on Gaussian finite mixtures is proposed as an extension to sliced inverse regression (SIR). The model-based SIR (MSIR) approach allows the main limitation of SIR to be overcome, i.e., failure in the presence of regression symmetric relationships, without the need to impose further…

2015-08-10abs ↗pdf ↗

New method for community detection in sparse directed SBMs with exact recovery guarantees.

problem Exact recovery in sparse directed SBMs, especially with growing communities.
method Two-stage procedure: neighborhood-smoothing followed by KK-means clustering.
result Exact recovery of all community labels with probability tending to one under mild sparsity and separation conditions.

The paper tackles learning varying DAG structures based on contextual features.

problem Learning a single DAG for the entire population from observational data.
method A neural network that maps contextual features to a weighted adjacency matrix of a DAG, with a projection layer to ensure acyclicity.
result The new approach can recover context-specific DAGs where existing methods fail.

Study on stochastic approximation with Polyak-Ruppert averaging for linear systems.

problem Understanding the asymptotic and non-asymptotic properties of stochastic approximation procedures.
method Detailed analysis of linear stochastic approximation with Polyak-Ruppert averaging, focusing on asymptotic and non-asymptotic properties.
result Proves CLT and non-asymptotic concentration inequality for averaged iterates, providing refined understanding of linear stochastic approximation.

Paper addresses concentration of distances for fractional quasi p-norms, identifying conditions for concentration and anti-concentration.

problem Understanding concentration of distances for fractional quasi p-norms in high dimensions.
method Analyzes conditions for concentration and anti-concentration of distances for fractional quasi p-norms.
result Identifies conditions for concentration and anti-concentration of fractional quasi p-norms, ruling out some approaches and specifying conditions for control.

Proves convergence of gradient Ricci shrinkers with uniform bounds.

problem Compactness and energy concentration in gradient Ricci shrinkers.
method Bubble-tree convergence and local energy analysis.
result No energy concentrates in neck regions, leading to a local diffeomorphism finiteness theorem.

Study Finsler metric measure manifolds' concentration properties.

problem Understanding concentration properties in Finsler metric measure manifolds.
method Established relationships with observable diameter, isoperimetric inequalities, and first eigenvalue.
result Derived a Cheng type upper bound estimate for the first closed eigenvalue.

Generative Adversarial Network (GAN) and its variants have recently attracted intensive research interests due to their elegant theoretical foundation and excellent empirical performance as generative models. These tools provide a promising direction in the studies where data availability is limited. One common issue i…

2018-02-19abs ↗pdf ↗

SGD noise helps select flat minima by concentrating in sharp directions and being proportional to loss value.

problem Understanding the implicit regularization of SGD and selecting flat minima in over-parameterized models.
method Relating SGD's linear stability to the Frobenius norm of the Hessian and analyzing the alignment property of SGD noise.
result Flat minima are linearly stable for SGD, and their sharpness is bounded independently of model size and sample size.

We give the first polynomial-time algorithm for robust regression in the list-decodable setting where an adversary can corrupt a greater than 1/21/2 fraction of examples. For any α<1α< 1, our algorithm takes as input a sample {(xi,yi)}in\{(x_i,y_i)\}_{i \leq n} of nn linear equations where αnαn of the equations satisfy $y_i = \l…

2019-05-14abs ↗pdf ↗

The paper shows robustness and generalization are closely connected via data-dependent bounds.

problem Connecting robustness and generalization in machine learning.
method Data-dependent generalization bounds that reduce dependence on covering number and hypothesis space.
result Proves robustness implies generalization, with near-exponential improvements in various situations.

We survey recent results related to the concentration of eigenfunctions. We also prove some new results concerning ball-concentration, as well as showing that eigenfunctions saturating lower bounds for L1L^1-norms must also, in a measure theoretical sense, have extreme concentration near a geodesic.

2015-10-26abs ↗pdf ↗