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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.

168,694 papers · 148 categories

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255075100 · May 202619922001200920172026
48 results for log-convex density

Geodesic balls are isoperimetric in hyperbolic spaces with certain densities.

problem Proving isoperimetric properties in hyperbolic spaces with specific densities.
method Using geodesic balls and radial, strictly log-convex densities.
result Geodesic balls are isoperimetric in real hyperbolic space HRnH_{\mathbb R}^n.

We completely characterize isoperimetric regions in R^n with density e^h, where h is convex, smooth, and radially symmetric. In particular, balls around the origin constitute isoperimetric regions of any given volume, proving the Log-Convex Density Conjecture due to Kenneth Brakke.

2013-11-16abs ↗pdf ↗

The classic double bubble theorem says that the least-perimeter way to enclose and separate two prescribed volumes in RN\mathbb{R}^N is the standard double bubble. We seek the optimal double bubble in RN\mathbb{R}^N with density, which we assume to be strictly log-convex. For N=1N=1 we show that the solution is sometime…

2017-08-10abs ↗pdf ↗

The paper proves new inequalities in hyperbolic space using Euclidean methods.

problem Proving weighted isoperimetric inequalities in hyperbolic space.
method Using isoperimetric inequality with log-convex density in Euclidean space.
result Removed horo-convex assumption and proved new inequalities for star-shaped domains.

We study the isoperimetric problem for Euclidean space endowed with a continuous density. In dimension one, we characterize isoperimetric regions for a unimodal density. In higher dimensions, we prove existence results and we derive stability conditions, which lead to the conjecture that for a radial log-convex density…

2006-02-07abs ↗pdf ↗

A new Bayesian filtering method speeds up stochastic Newton optimization.

problem Minimizing log-convex functions using stochastic methods.
method Contextualizes the problem as Bayesian inference, applying Bayesian filtering to update estimates.
result Establishes conditions for diminishing effect of older observations, akin to momentum.

Given a positive lower semi-continuous density ff on R2\mathbb{R}^2 the weighted volume Vf:=fL2V_f:=f\mathscr{L}^2 is defined on the L2\mathscr{L}^2-measurable sets in R2\mathbb{R}^2. The ff-weighted perimeter of a set of finite perimeter EE in R2\mathbb{R}^2 is written Pf(E)P_f(E). We study minimisers for the weighted isop…

2016-12-21abs ↗pdf ↗

Sharp comparison theorems are derived for all eigenvalues of the (weighted) Laplacian, for various classes of weighted-manifolds (i.e. Riemannian manifolds endowed with a smooth positive density). Examples include Euclidean space endowed with strongly log-concave and log-convex densities, extensions to pp-exponential …

2015-08-03abs ↗pdf ↗

Study fine Pólya-Szegő inequalities in metric spaces with applications.

problem Fine Pólya-Szegő rearrangement inequalities in metric spaces.
method Theory of Sobolev and BV functions, synthetic Ricci bounds, isoperimetric inequality.
result New geometric and functional inequalities under Ricci lower bounds.

Proves monotonicity of parabolic frequency on all manifolds without curvature assumptions.

problem Monotonicity of parabolic frequency on manifolds.
method Analyzes parabolic frequency function on manifolds, proving monotonicity without curvature assumptions.
result Monotonicity of parabolic frequency on all manifolds, no curvature assumption needed.

In our previous paper [SIMAX 31 n.3 1491-1506(2010)], we studied the condition metric in the space of maximal rank matrices. Here, we show that this condition metric induces a Lipschitz-Riemann structure on that space. After investigating geodesics in such a nonsmooth structure, we show that the inverse of the smallest…

2009-10-30abs ↗pdf ↗

Optimizes dividend control in a bankruptcy process using a special Levy process.

problem Optimizing dividend payouts in a bankruptcy process.
method Using a non-standard spectrally negative Levy process with endogenous regime switching.
result Optimal dividend control is of the barrier type and the optimal barrier can be identified.

Let C[M]C^{[M]} be a (local) Denjoy-Carleman class of Beurling or Roumieu type, where the weight sequence M=(Mk)M=(M_k) is log-convex and has moderate growth. We prove that the groups DiffB[M](Rn){\operatorname{Diff}}\mathcal{B}^{[M]}(\mathbb{R}^n), DiffW[M],p(Rn){\operatorname{Diff}}W^{[M],p}(\mathbb{R}^n), ${\operatorname{Diff}}{\mathcal{S}}{}_…

2014-04-28abs ↗pdf ↗

We prove the exponential law A(E×F,G)A(E,A(F,G))\mathcal A(E \times F, G) \cong \mathcal A(E,\mathcal A(F,G)) (bornological isomorphism) for the following classes A\mathcal A of test functions: B\mathcal B (globally bounded derivatives), W,pW^{\infty,p} (globally pp-integrable derivatives), S\mathcal S (Schwartz space), D\mathcal D

2014-11-03abs ↗pdf ↗

MCD reformulates conditional density estimation into binary classification.

problem Conditional density estimation in statistical and machine learning.
method Marginal Contrastive Discrimination, reformulating into marginal and ratio density functions for binary classification.
result Significantly outperforms existing methods on most density models and regression datasets.

Paper proposes MMC to avoid high-density bias in clustering.

problem High-density bias in density-based clustering.
method Introduces mass distribution as a better foundation for clustering, proposing mass-maximization clustering (MMC).
result MMC avoids high-density bias and discovers clusters of arbitrary shapes, sizes, and densities.

New method minimizes robust density power-based divergences for general parametric densities.

problem Computational complexity of minimizing DPD for general parametric densities.
method Stochastic approach to minimize DPD for general parametric density models.
result Proposed method can be applied to minimize other density power-based γ-divergences.

Study exact minimax rates for density estimation over convex classes, extending previous work.

problem Deriving minimax rates for density estimation over convex density classes.
method Building on Le Cam's work, determine exact minimax rates using local metric entropy.
result Exact minimax rates derived for any convex density class, including nonparametric and parametric cases.

New method uses SoS densities and α-divergences for efficient sequential transport maps.

problem Efficiently generating samples from approximated densities.
method Sequential transport maps using Sum-of-Squares (SoS) densities and α-divergences.
result Convex optimization problems with efficient semidefinite programming solutions.

The volume density of a hyperbolic link is defined as the ratio of hyperbolic volume to crossing number. We study its properties and a closely-related invariant called the determinant density. It is known that the sets of volume densities and determinant densities of links are dense in the interval [0,v_{oct}]. We cons…

2015-10-20abs ↗pdf ↗

TAKDE optimizes kernel density estimation for real-time dynamic processes.

problem Real-time density estimation in applications like computer vision and signal processing.
method Derives asymptotic mean integrated squared error (AMISE) upper bound for 'sliding window' kernel density estimator and proposes TAKDE as a novel, theoretically optimal estimator.
result TAKDE outperforms other dynamic density estimators in terms of test log-likelihood and runtime.

Optimizes kernel density ratios for better predictions and information measures.

problem Improving accuracy of kernel density estimates for density ratios.
method Derives an optimal weight function using calculus of variations.
result Reduces bias in kernel density estimates, leading to improved prediction posteriors and information-theoretic measures.

We introduce a novel conditional density estimation model termed the conditional density operator (CDO). It naturally captures multivariate, multimodal output densities and shows performance that is competitive with recent neural conditional density models and Gaussian processes. The proposed model is based on a novel …

2019-05-27abs ↗pdf ↗

Quantum method improves neural density estimation in high dimensions.

problem High-dimensional density estimation with poor performance and high computational complexity.
method Adaptive Fourier features based on quantum density matrices, integrated with neural networks.
result Competitive performance compared to state-of-the-art methods in various datasets.

Defines hierarchical clustering axioms for various densities.

problem Defining hierarchical clustering for different types of densities.
method An axiomatic approach to piecewise constant densities, then extending to general densities.
result Our axiomatic definition results in Hartigan's cluster tree under certain conditions.

The paper analyzes kNN density estimation's convergence rates under different conditions.

problem Analyzing convergence rates of kNN density estimation under bounded and unbounded support conditions.
method Examined two cases: bounded support with known and unknown support sets, and unbounded support with smooth density function.
result kNN density estimation is minimax optimal under certain conditions and better than kernel density estimation in some cases.

Develops spherical density-equalizing maps for closed surfaces.

problem Lack of methods for genus-0 closed surfaces.
method Conformal parameterization onto unit sphere, density equalization, quasi-conformal theory, harmonic energy, landmark constraints.
result Landmark-aligned spherical density-equalizing maps balancing different distortion measures.

Method uses normalizing flows to efficiently sample from complex target densities.

problem Sampling from complex target densities with zero values in regions of transformation.
method Normalizing flows to address exploding reverse Kullback-Leibler divergence.
result Demonstrated efficient sampling from multi-mode complex density function.