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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.

169,341 papers · 148 categories

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19385675 · Jul 202619922001200920182026
48 results for nonzero coefficients

Paper introduces ENZ to measure significant coefficients in sparse recovery, improving over classical methods.

problem Numerical noise creates long tails of negligible coefficients in sparse recovery.
method Entropy-based notion of effective sparsity (ENZ) to measure significant coefficients, proving stability under restricted isometry condition.
result ENZ decomposes into support cardinality and efficiency factor, providing a precise measure of sparsity.

A number of recent work studied the effectiveness of feature selection using Lasso. It is known that under the restricted isometry properties (RIP), Lasso does not generally lead to the exact recovery of the set of nonzero coefficients, due to the looseness of convex relaxation. This paper considers the feature selecti…

2011-06-03abs ↗pdf ↗

Extends Morse-Novikov Homology to include differential graded coefficients and fibration structures.

problem Extending Morse-Novikov Homology with differential graded coefficients.
method Constructs a Morse-Novikov complex and proves the existence of a Chas-Sullivan-like product for a fibration.
result Proves the existence of a Chas-Sullivan-like product on the Novikov completion of a fibration.

New properties are derived of renormalized volume functionals, which arise as coefficients in the asymptotic expansion of the volume of an asymptotically hyperbolic Einstein (AHE) manifold. A formula is given for the renormalized volume of an even-dimensional AHE manifold in terms of an arbitrary totally geodesic compa…

2012-11-27abs ↗pdf ↗

A new estimator minimizes non-zero coefficients with a budget on feature-residual correlation.

problem Sparse linear model estimation with feature-residual correlation constraints.
method Mixed Integer Linear Optimization (MILO) for certifiably optimal global solutions.
result Discrete Dantzig Selector provides globally optimal solutions faster than existing methods.

This paper bounds the computational cost of computing the Kauffman bracket of a link in terms of the crossing number of that link. Specifically, it is shown that the image of a tangle with gg boundary points and nn crossings in the Kauffman bracket skein module is a linear combination of O(2g)O(2^g) basis elements, with…

2013-03-28abs ↗pdf ↗

We show that for acylindrically hyperbolic groups ΓΓ (with no nontrivial finite normal subgroups) and arbitrary unitary representation ρρ of ΓΓ in a (nonzero) uniformly convex Banach space the vector space Hb2(Γ;ρ)H^2_b(Γ;ρ) is infinite dimensional. The result was known for the regular representations on p(Γ)\ell^p(Γ) with …

2013-06-06abs ↗pdf ↗

Computer algebra methods are applied to investigation of spectral asymptotics of elliptic differential operators on curved manifolds with torsion and in the presence of a gauge field. In this paper we present complete expressions for the second coefficient (E_2) in the heat kernel expansion for nonminimal operator on m…

2000-04-13abs ↗pdf ↗

New method for MTL with varying sparsity patterns across tasks.

problem Jointly training multiple linear models with differing sparsity patterns.
method Mixed-integer programming formulation and scalable algorithms.
result Our methods leverage shared support information to improve variable selection.

We make a detailed study of the Heegaard Floer homology of the product of a closed surface Sigma_g of genus g with S^1. We determine HF^+ for this 3-manifold completely for the spin^c structure having trivial first Chern class, which for g>2 was previously unknown. We show that in this case HF^\infty is closely related…

2005-02-15abs ↗pdf ↗

Researchers find examples of real Bott manifolds with nonzero dual Stiefel-Whitney class wbar_{n-ahat(n)} for all n nonzero mod 4.

problem Finding compact orientable manifolds with nonzero dual Stiefel-Whitney classes of largest possible grading.
method Constructing real Bott manifolds for all n nonzero mod 4.
result Examples of real Bott manifolds with the desired property are found for all n nonzero mod 4.

For a closed n-braid L with a full positive twist and with k negative crossings, 0\leq k \leq n, we determine the first n-k+1 terms of the Jones polynomial V_L(t). We show that V_L(t) satisfies a braid index constraint, which is a gap of length at least n-k between the first two nonzero coefficients of (1-t^2)V_L(t). F…

2010-04-15abs ↗pdf ↗

For a surface FF, the Kauffman bracket skein module of F×[0,1]F \times [0,1], denoted K(F)K(F), admits a natural multiplication which makes it an algebra. When specialized at a complex number tt, nonzero and not a root of unity, we have Kt(F)K_t(F), a vector space over C\mathbb{C}. In this paper, we will use the product-to-su…

2006-03-14abs ↗pdf ↗

SNAP solves LASSO and Enet efficiently with optimal convergence rates.

problem Sparse, high-dimensional linear regression with LASSO and Enet penalties.
method Semismooth Newton algorithm based on KKT conditions, warm start, and support seeking.
result SNAP converges locally superlinearly for Enet and optimally for LASSO, achieving sharp estimation error bounds.

Explicit formulas for Hattori-Stong integrability conditions and manifolds' signature properties.

problem Understanding and calculating the signature of stably almost-complex manifolds.
method Combinatorial techniques to derive explicit formulas for Chern class coefficients and signature conditions.
result An evenness condition for the signature of stably almost-complex manifolds in terms of Chern numbers.

The nonzero level sets of a homogeneous, logarithmically homogeneous, or translationally homogeneous function are affine spheres if and only if the Hessian determinant of the function is a multiple of a power or an exponential of the function. In particular, the nonzero level sets of a homogeneous polynomial are proper…

2013-07-20abs ↗pdf ↗

New formulas for barrier options in stochastic volatility models with nonzero correlation.

problem Calculating barrier options prices in models with nonzero correlation.
method Derivation of two novel closed-form formulas: Hull and White type and Alòs-like decomposition.
result Closed-form formulas for barrier options in stochastic volatility models with nonzero correlation.

In this paper, it is shown that every orientable closed 3-manifold maps with nonzero degree onto at most finitely many homeomorphically distinct irreducible non-geometric orientable closed 3-manifolds. Moreover, given any nonzero integer, as a mapping degree up to sign, every orientable closed 3-manifold maps with that…

2011-07-29abs ↗pdf ↗

Paper shows peeling property for Bondi-Sachs metrics with nonzero cosmological constant.

problem Investigating the peeling property of Bondi-Sachs metrics with cosmological constant.
method Using Sommerfeld's radiation condition and three nontrivial functions, constructing nonstationary vacuum metrics.
result Peeling property holds for Bondi-Sachs metrics with nonzero cosmological constant.

Improved SGD learning for single index models reduces sample complexity.

problem Learning a single index model with optimal sample complexity.
method Using smoothed loss in online SGD to reduce sample complexity.
result Online SGD with smoothed loss achieves optimal sample complexity of dk/2d^{k^\star/2}.

Paper proves biharmonic hypersurfaces in nonzero space form have constant mean curvature.

problem Proving constant mean curvature for biharmonic hypersurfaces.
method Careful analysis of Gauss and Codazzi equations.
result Positive answer to Balmus-Montaldo-Oniciuc's conjecture for four dimensional hypersurfaces.

Study identifies conditions for a dictionary to be uniquely identifiable from signals.

problem Identifying a unique dictionary from random linear combinations of signals.
method Analyzes l1l_1-minimization for NN signals generated from a complete reference dictionary with random coefficients.
result Establishes a sufficient and almost necessary condition for local identifiability of the reference dictionary.

This paper improves lower bounds for the first nonzero Steklov eigenvalue on compact manifolds.

problem Finding lower bounds for the first nonzero Steklov eigenvalue on compact manifolds.
method Constructing a new weight function under certain sectional curvature assumptions and using integral identities.
result New lower bounds for the first nonzero Steklov eigenvalue are provided, generalizing previous results.

We add a set of convex constraints to the lasso to produce sparse interaction models that honor the hierarchy restriction that an interaction only be included in a model if one or both variables are marginally important. We give a precise characterization of the effect of this hierarchy constraint, prove that hierarchy…

2012-05-22abs ↗pdf ↗

The sinh-Gordon equation is solved on finite, symmetric graphs.

problem Solving the sinh-Gordon equation with nonzero prescribed functions on finite graphs.
method Uniform a priori estimate to define topological degree, case-by-case calculation of degree, classical sinh-Gordon equation analysis.
result The classical sinh-Gordon equation with nonzero prescribed function is always solvable on finite, symmetric graphs.

Given a compact Riemannian spin manifold with positive scalar curvature, we find a family of connections At\nabla^{A_t} for t[0,1]t\in[0,1] on a trivial vector bundle of sufficiently high rank, such that the first eigenvalue of the twisted Dirac operator DAtD_{A_t} is nonzero and becomes arbitrarily small as t1t\to1. Howeve…

2008-07-04abs ↗pdf ↗

In multi-label learning, each sample is associated with several labels. Existing works indicate that exploring correlations between labels improve the prediction performance. However, embedding the label correlations into the training process significantly increases the problem size. Moreover, the mapping of the label …

2011-03-01abs ↗pdf ↗