Research
On-device research index

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

Trend · papers per month

336699132 · May 202619922001200920172026
48 results for exactness

Study on compact manifolds for exact G2_{2}-Structures without additional constraints.

problem Whether compact 7-manifolds support exact G2_{2}-Structures.
method Investigate exact G2_{2}-Structures on compact manifolds, considering relationships with other conditions.
result Initiate a study on exact G2_{2}-Structures on compact manifolds without additional constraints.

Exact selective inference with randomization for Gaussian regression models.

problem Exact selective inference in Gaussian regression models.
method Introduces a pivot for exact selective inference with randomization, reducing the problem to a bivariate truncated Gaussian distribution.
result Our pivot leads to exact inference and produces narrower confidence intervals than related methods.

For a Legendrian (2,n)(2,n) torus knot or link with maximal Thurston-Bennequin number, Ekholm, Honda, and Kálmán constructed CnC_n exact Lagrangian fillings, where CnC_n is the nn-th Catalan number. We show that these exact Lagrangian fillings are pairwise non-isotopic through exact Lagrangian isotopy. To do that, we com…

2016-07-11abs ↗pdf ↗

Between the category of exact metric spaces with bounded geometry (about which much is known) and the larger category of arbitrary exact metric spaces (about which little is known) lies the intermediate category of asymptotically exact metric spaces. We show that the coarse Baum-Connes assembly map is naturally split s…

2012-06-13abs ↗pdf ↗

Exact optimality achieved in distributed mean estimation with shared randomness.

problem Achieving optimal communication, privacy, and utility tradeoffs in distributed mean estimation.
method Utilization of a rotationally symmetric shared random codebook and a kk-closest encoding mechanism.
result Proposed mechanism achieves exact optimality for randomly rotated simplex codebook.

We show that if a contact open book (Σ,h)(Σ,h) on a (2n+1)(2n+1)-manifold MM (n1n\geq1) is induced by a Lefschetz fibration π:WD2π:W \to D^2, then there is a one-to-one correspondence between positive stabilizations of (Σ,h)(Σ,h) and \emph{positive stabilizations} of ππ. More precisely, any positive stabilization of (Σ,h)(Σ,h) is in…

2011-12-02abs ↗pdf ↗

Paper explores exact recovery of communities in weighted graphs using Gaussian and exponential distributions.

problem Exact recovery of communities in weighted graphs with Gaussian and exponential distributions.
method Introduces a new semi-metric to describe conditions for exact recovery and analyzes conditions for both complete and incomplete graphs.
result Necessary and sufficient conditions for exact recovery are asymptotically tight and applicable to both complete and incomplete graphs.

Exact Bayesian inference for discrete models using probability generating functions.

problem Discrete statistical models with infinite support and continuous priors.
method Probabilistic programming language with automatic differentiation and probability generating functions.
result Genfer tool provides exact solutions for a wide range of inference problems.

No exact G₂-structures on compact Lie group quotients.

problem Existence of exact G₂-structures on compact quotients of Lie groups.
method Analyzing compact quotients of seven-dimensional Lie groups by co-compact discrete subgroups.
result Compact quotients of seven-dimensional Lie groups by co-compact discrete subgroups do not admit exact G₂-structures induced by left-invariant ones.

We introduce constructions of exact Lagrangian cobordisms with cylindrical Legendrian ends and study their invariants which arise from Symplectic Field Theory. A pair (X,L)(X,L) consisting of an exact symplectic manifold XX and an exact Lagrangian cobordism LXL\subset X which agrees with cylinders over Legendrian links $…

2012-12-07abs ↗pdf ↗

New surgery exact triangles in Heegaard Floer homology for rational slopes.

problem Constructing new surgery exact triangles in Heegaard Floer homology.
method Combining combinatorial triangle and quadrilateral counting in genus 1 Heegaard diagrams.
result Solving the combinatorial problem for rational slopes, including tricky cases.

Paper explores limits of exact inference in structured prediction models.

problem Exact recovery of true labels in graph-based structured prediction models.
method Analyzes necessary and sufficient conditions for exact recovery using maximum likelihood estimation.
result Derives tight conditions for exact recovery, revealing a gap with computationally tractable methods.

We provide in this note two relevant examples of Lagrangian cobordisms. The first one gives an example of two exact Lagrangian submanifolds which cannot be composed in an exact fashion. The second one is an example of an exact Lagrangian cobordism on which all primitive of the Liouville form is not constant on the nega…

2013-01-29abs ↗pdf ↗

Exact second-order optimization for deep learning reduces computational cost and improves performance.

problem Inadequate use of second-order optimization methods in deep learning due to high computational cost and non-convexity.
method Developed an exact stochastic second-order Newton method that addresses the non-convexity issue and provides an expression for the stochastic Hessian.
result Exact second-order Newton direction formula and its application in deep learning datasets.

This paper answers a basic question about the Birman exact sequence in the theory of mapping class groups. We prove that the Birman exact sequence does not admit a section over any subgroup ΓΓ contained in the Torelli group with finite index. A fortiori this proves that there is no section of the Birman exact sequence…

2018-04-30abs ↗pdf ↗

To a Legendrian knot, one can associate an A\mathcal{A}_{\infty} category, the augmentation category. An exact Lagrangian cobordism between two Legendrian knots gives a functor of the augmentation categories of the two knots. We study the functor and establish a long exact sequence relating the corresponding cohomolog…

2016-06-19abs ↗pdf ↗

New conditions ensure Dantzig-Wolfe relaxation matches rank-constrained optimization problems.

problem Rank-constrained optimization problems with linear matrix inequalities.
method Investigates Dantzig-Wolfe relaxation and develops conditions for exactness.
result Conditions for extreme point, convex hull, and objective exactness.

We determine the information-theoretic cutoff value on separation of cluster centers for exact recovery of cluster labels in a KK-component Gaussian mixture model with equal cluster sizes. Moreover, we show that a semidefinite programming (SDP) relaxation of the KK-means clustering method achieves such sharp threshol…

2020-01-05abs ↗pdf ↗

We study graph matching with correlated Gaussian features and find thresholds for exact recovery.

problem Graph matching with correlated Gaussian features.
method Information-theoretic thresholds and conditions for exact and almost exact recovery.
result Contextual information introduces a richer structure, with thresholds for exact and almost exact recovery no longer coinciding.

Exact learning improves naive Bayes classifier performance for small samples.

problem Improving naive Bayes classifier performance with small sample sizes.
method Proposes an exact learning augmented naive Bayes classifier (ANB) that ensures a class variable with no parents.
result The proposed ANB method outperforms other methods in comparison experiments.

The exact nonnegative matrix factorization (exact NMF) problem is the following: given an mm-by-nn nonnegative matrix XX and a factorization rank rr, find, if possible, an mm-by-rr nonnegative matrix WW and an rr-by-nn nonnegative matrix HH such that X=WHX = WH. In this paper, we propose two heuristics for exac…

2014-11-26abs ↗pdf ↗

PhD dissertation on Finsler geometry and gravity, focusing on Berwald spaces and exact solutions.

problem Characterizing and solving Finsler gravity equations.
method Analysis of Berwald spaces, (α,β)(α,β)-metrics, and exact solutions to Finsler gravity equations.
result Exact vacuum solutions in Finsler gravity.

We study some properties of decomposable exact Lagrangian cobordisms between Legendrian links in R3\mathbb{R}^3 with the standard contact structure. In particular, for any decomposable exact Lagrangian filling LL of a Legendrian link KK, we may obtain a normal ruling of KK associated with LL. We prove that the asso…

2015-12-26abs ↗pdf ↗

The article provides obstructions for exact submanifolds in symplectic applications.

problem Existence of exact submanifolds with specific homology classes.
method Study of formal deformations of the de Rham complex to compute obstructions.
result Symplectic manifolds like Kähler and Kodaira-Thurston admit no non-separating exact hypersurfaces.

Sharp threshold for exact recovery in non-uniform hypergraph stochastic block model.

problem Community detection in random hypergraphs with non-uniform hyperedge probabilities.
method Sharp threshold established; two efficient algorithms for exact recovery.
result Sharp threshold for exact recovery; information-theoretic lower bound on misclassification.

New exact sequence links cohomology, automorphisms, and extensions of symmetric quandles.

problem Understanding the structure of extensions and automorphisms in symmetric quandles.
method Derived a four-term exact sequence relating 1-cocycles, second cohomology, and automorphisms.
result Obstruction to automorphisms lies in the second cohomology of symmetric quandles.

We develop an analogue of the Birman exact sequence for the Torelli subgroup of Aut(F_n). This builds on earlier work of the authors who studied an analogue of the Birman exact sequence for the entire group Aut(F_n). These results play an important role in the authors' recent work on the second homology group of the To…

2015-07-31abs ↗pdf ↗