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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.

168,738 papers · 148 categories

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3672107143 · May 202619922001200920172026
48 results for Liénard equations

NARD extends ARD for linear models, promoting sparsity and correlation structure.

problem Sparse relationships between inputs and outputs, capturing correlation structure.
method Matrix normal prior with sparsity-inducing parameter, iterative updates, sequential evaluation, and surrogate function approximation.
result Significant computational efficiency improvements with comparable performance.

Derives gradient estimate for a specific nonlinear parabolic equation on Finsler manifolds.

problem Derives gradient estimate for a nonlinear parabolic equation on Finsler manifolds.
method Leverages a new Laplacian comparison theorem to derive a Li-Yau type gradient estimate.
result Establishes a Li-Yau type gradient estimate for the Finslerian logarithmic Schrödinger equation.

Derives gradient bounds for f-heat equations on manifolds with Bakry-Emery Ricci curvature.

problem Gradient estimates for positive solutions of f-heat equations on manifolds with specific curvature conditions.
method Applies Li-Yau gradient estimates to positive solutions of the f-heat equation on closed manifolds with Bakry-Emery Ricci curvature bounded below.
result Derives Li-Yau gradient bounds for positive solutions of the f-heat equation.

In this paper, we obtain a Li-Yau type gradient estimate with time dependent parameter for positive solutions of the heat equation, so that the Li-Yau type gradient estimate of Li-Xu are special cases of the estimate. We also obtain improvements of Davies' Li-Yau type gradient estimate. The argument is different with t…

2017-06-20abs ↗pdf ↗

The paper derives new gradient and Hessian estimates for nonlinear parabolic equations.

problem Estimating solutions to nonlinear weighted parabolic equations.
method Derives Li-Yau and Hamilton type gradient estimates, and Hessian estimates.
result New gradient and Hessian estimates for positive solutions of nonlinear parabolic equations.

Paper proves estimates for heat and conjugate heat equations under Ricci flow, leading to monotonicity of parabolic frequencies.

problem Establishing estimates for heat and conjugate heat equations under Ricci flow.
method Proving matrix Li-Yau-Hamilton estimates for positive solutions to the heat and conjugate heat equations coupled with Ricci flow.
result Monotonicity of parabolic frequencies established up to correction factors.

We derive an interpolation version of constrained matrix Li-Yau-Hamilton estimate on Kähler manifolds. As a result, we first get a constrained matrix Li-Yau-Hamilton estimate for heat equation on a Kähler manifold with fixed Kähler metric. Secondly, we get a corresponding estimate for forward conjugate heat equation on…

2014-07-01abs ↗pdf ↗

We prove a generalization of the Li-Yau estimate for a board class of second order linear parabolic equations. As a consequence, we obtain a new Cheeger-Yau inequality and a new Harnack inequality for these equations. We also prove a Hamilton-Li-Yau estimate, which is a matrix version of the Li-Yau estimate, for these …

2012-11-23abs ↗pdf ↗

In this paper, we obtain Li-Yau type gradient estimates with time dependent parameter for positive solutions of the heat equation that are different with the estimates by Li-Xu \cite{LX} and Qian \cite{Qi}. As an application of the estimate, we also obtained improvements of Davies' Li-Yau type gradient estimate.

2017-05-22abs ↗pdf ↗

In this paper, motivated by the works of Bakry et. al in finding sharp Li-Yau type gradient estimate for positive solutions of the heat equation on complete Riemannian manifolds with nonzero Ricci curvature lower bound, we first introduce a general form of Li-Yau type gradient estimate and show that the validity of suc…

2018-07-16abs ↗pdf ↗

Directly proves Li-Yau estimates on manifolds with negative Ricci curvature.

problem Proving Li-Yau estimates on manifolds with negative Ricci curvature.
method Uses classical maximum principle argument and Hamilton's techniques.
result Directly proves sharp Li-Yau estimates simplifying previous methods.

The paper establishes sub-gradient estimates and entropy formulas for quaternionic contact geometry heat equations.

problem Developing sub-gradient estimates and entropy formulas for quaternionic contact geometry.
method Establishing sub-gradient estimates and entropy formulas for the quaternionic contact heat equation.
result Two Perelman-type entropy formulas and sub-gradient estimates for the quaternionic contact heat equation.

Derives matrix Harnack inequalities for semilinear heat equations on manifolds.

problem Bounding solutions of semilinear heat equations on manifolds with geometric constraints.
method Applies Li-Yau estimates to derive Harnack inequalities for positive solutions.
result Derives matrix Harnack inequalities for positive solutions of semilinear heat equations.

Improved heat equation estimates without gradient curvature assumption.

problem Improving Hamilton's matrix Harnack estimate for heat equation without gradient curvature assumption.
method New ingredients include a sharp Li-Yau estimate, a suitable vector field construction, and integral arguments.
result Removed the gradient curvature assumption in Hamilton's estimate for heat equation.

The paper derives gradient estimates for porous medium and fast diffusion equations on metric measure spaces.

problem Gradient estimates for porous medium and fast diffusion equations on metric measure spaces.
method Derives Li-Yau and Souplet-Zhang type gradient estimates for the given equations.
result Gradient estimates for the equations on complete noncompact metric measure spaces with compact boundary.

Researchers prove inequalities for reaction-diffusion systems using a new curvature-dimension condition.

problem Proving Li-Yau and Harnack inequalities for systems of linear reaction-diffusion equations.
method Introducing a hybrid curvature-dimension condition and proving a differential Harnack estimate.
result A Harnack inequality holds under the hybrid curvature-dimension condition CDhyb(0,d)CD_{hyb} (0,d) with d<d<\infty.

In this paper we are concerned with the matrix Li-Yau-Hamilton estimates for nonlinear heat equations. Firstly, we derive such estimate on a Kähler manifold with a fixed Kähler metric. Then we consider the estimate on Kähler manifolds with Kähler metrics evolving under the rescaled Kähler-Ricci flow. Both of the estima…

2019-11-01abs ↗pdf ↗

In this paper we study gradient estimates for the positive solutions of the porous medium equation: ut=Δumu_t=Δu^m where m>1m>1, which is a nonlinear version of the heat equation. We derive local gradient estimates of the Li-Yau type for positive solutions of porous medium equations on Riemannian manifolds with Ricci curv…

2011-06-13abs ↗pdf ↗

The study shows how to foliate convex hypersurfaces in affine space with constant curvature.

problem Finding convex hypersurfaces with constant Gauss-Kronecker curvature in affine space.
method Solving a Monge-Ampère equation with specific boundary conditions.
result Regular domains in affine space are foliated by complete convex hypersurfaces with constant Gauss-Kronecker curvature.

The paper improves heat equation estimates under weaker Ricci curvature conditions.

problem Improving heat equation estimates under weaker Ricci curvature conditions.
method Establishing Li-Yau-type and Hamilton-type estimates for positive solutions of the heat equation under generalized Ricci flow.
result Deriving Harnack-type inequalities and monotonicity of parabolic frequency.

The paper derives gradient estimates for solutions of certain equations on metric measure spaces.

problem Gradient estimates for solutions of specific nonlinear and elliptic equations on metric measure spaces.
method Derives Li-Yau and Hamilton's type gradient estimates for positive solutions.
result Gradient estimates for positive solutions of the equations on complete noncompact metric measure spaces.

We give a proof to the Li-Yau-Hamilton type inequality claimed by Perelman on the fundamental solution to the conjugate heat equation. The rest of the paper is devoted to improving the known differential inequalities of Li-Yau-Hamilton type via monotonicity formulae.

2006-02-15abs ↗pdf ↗

Develops Lie-theoretic perspective on Hitchin's equations for cyclic G-Higgs bundles.

problem Analytic and geometric properties of harmonic maps.
method Lie-theoretic perspective on Hitchin's equations for cyclic G-Higgs bundles.
result Proves Dai-Li's conjecture on the monotonicity of the energy density and negative curvature conjecture for Coxeter cyclic G-Higgs bundles.

We prove a Li-Yau gradient estimate for positive solutions to the heat equation, with Neumann boundary conditions, on a compact Riemannian submanifold with boundary MnNn{\bf M}^n\subseteq {\bf N}^n, satisfying the integral Ricci curvature assumption: \begin{equation} D^2 \sup_{x\in {\bf N}} \left( \oint_{B(x,D)} |Ric^-|^…

2017-10-24abs ↗pdf ↗

Existence of convex body with prescribed generalized curvature measures is discussed, this result is obtained by making use of Guan-Li-Li's innovative techniques. In surprise, that methods has also brought us to promote Ivochkina's C2C^2 estimates for prescribed curvature equation in \cite{I1, I}.

2011-04-27abs ↗pdf ↗

This paper proves Liouville theorems for conformally invariant fully nonlinear equations.

problem Positive entire solutions of certain fully nonlinear equations are unique.
method Derives necessary and sufficient conditions for Liouville-type theorems.
result Enhanced understanding of solutions near isolated singularities.

In this paper we derive Cheng-Yau, Li-Yau, Hamilton estimates for Riemannian manifolds with Bakry-Emery Ricci curvature bounded from below, and also global and local upper bounds, in terms of Bakry-Emery Ricci curvature, for the Hessian of positive and bounded solutions of the weighted heat equation on a closed Riemann…

2014-06-01abs ↗pdf ↗

In this paper, we study Li-Yau gradient estimates for the solutions uu to the heat equation tu=Δu\partial_tu=Δu on graphs under the curvature condition CD(n,K)CD(n,-K) introduced by Bauer et al. in \cite{BHLLMY}. As applications, we derive Harnack inequalities and heat kernel estimates on graphs. Also we present a type of Ham…

2013-11-14abs ↗pdf ↗

Let $(\M^n, g_{ij})$ be a complete Riemammnian manifold. For some constants p, r>0p,\ r>0, define k(p,r)=supxMr2(B(x,r)RicpdV)1/p\displaystyle k(p,r)=\sup_{x\in M}r^2\left(\oint_{B(x,r)}|Ric^-|^p dV\right)^{1/p}, where RicRic^- denotes the negative part of the Ricci curvature tensor. We prove that for any p>n2p>\frac{n}{2}, when k(p,1)k(p,1) is small enough,…

2016-07-20abs ↗pdf ↗

The paper provides gradient estimates for nonlinear heat-type equations on smooth metric measure spaces.

problem Proving gradient estimates for nonlinear heat-type equations on smooth metric measure spaces.
method Using Hamilton type and Li-Yau type estimates, the paper proves gradient estimates on positive solutions to generalized nonlinear parabolic equations on smooth metric measure spaces with compact boundary.
result Gradient estimates for nonlinear heat-type equations on smooth metric measure spaces.