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.

168,742 papers · 148 categories

Trend · papers per month

3672108144 · Jun 202019922001200920172026
48 results for modified m-Bakry-Emery Ricci tensor

The paper proves Laplacian comparison theorems for modified m-Bakry-Emery Ricci tensors on Riemannian manifolds.

problem Analyzing modified m-Bakry-Emery Ricci tensors on Riemannian manifolds.
method Proving Laplacian comparison theorems using modified m-Bakry-Emery Ricci tensors under m≤1.
result Optimal conditions for modified m-Bakry-Emery Ricci tensors under m≤1 are derived.

We show that near-horizon geometries in the presence of a positive cosmological constant cannot exist with ring topology. In particular, de Sitter black rings with vanishing surface gravity do not exist. Our result relies on a known mathematical theorem which is a straightforward consequence of a type of energy conditi…

2017-08-11abs ↗pdf ↗

We call a metric quasi-Einstein if the mm-Bakry-Emery Ricci tensor is a constant multiple of the metric tensor. This is a generalization of Einstein metrics, which contains gradient Ricci solitons and is also closely related to the construction of the warped product Einstein metrics. We study properties of quasi-Einst…

2008-05-20abs ↗pdf ↗

We call a metric mm-quasi-Einstein if RicXmRic_X^m (a modification of the mm-Bakry-Emery Ricci tensor in terms of a suitable vector field XX) is a constant multiple of the metric tensor. It is a generalization of Einstein metrics which contains Ricci solitons. In this paper, we focus on left-invariant vector fields and…

2014-01-09abs ↗pdf ↗

The paper proves inequalities under Bakry-Émery-Ricci curvature bounds.

problem Proving functional inequalities under lower Bakry-Émery-Ricci curvature bounds.
method Lower mm-Bakry-Émery-Ricci curvature bounds with ε\varepsilon-range.
result Proves Cheng type inequality and local Sobolev inequality.

We study the properties of Modified Riemann extensions evolving under Ricci flow. We obtain the necessary and sufficient condition for modified Riemann extension under Ricci flow to stay as modified Riemann extension. We also discuss the properties of the curvature tensors under Ricci flow.

2015-05-03abs ↗pdf ↗

The paper proves a Laplacian comparison theorem on weighted Riemannian manifolds and applies it to diffusion processes.

problem Analyzing diffusion processes on Riemannian manifolds with weighted metrics.
method Proving a Laplacian comparison theorem and applying it to various geometric and analytic properties of diffusion processes.
result Optimal conditions on mm-Bakry-Émery Ricci tensor for various geometric and analytic properties to hold on weighted complete Riemannian manifolds.

Scalar-tensor gravitation theories, such as the Brans-Dicke family of theories, are commonly partly described by a modified Einstein equation in which the Ricci tensor is replaced by the Bakry-Émery-Ricci tensor of a Lorentzian metric and scalar field. In physics this formulation is sometimes referred to as the "Jordan…

2013-10-15abs ↗pdf ↗

The aim of this note is to study the measure-valued Ricci tensor on smooth metric measure space with boundary, which is a generalization of Bakry-Emery's modified Ricci tensor on weighted Riemannian manifold. As an application, we offer a new approach to study curvature-dimension condition of smooth metric measure spac…

2017-09-28abs ↗pdf ↗

We call a metric mm-quasi-Einstein if RicXmRic_X^m, which replaces a gradient of a smooth function ff by a vector field XX in mm-Bakry-Emery Ricci tensor, is a constant multiple of the metric tensor. It is a generalization of Einstein metrics which contains Ricci solitons. In this paper, we focus on left-invariant met…

2013-10-30abs ↗pdf ↗

Paper finds lower bounds for eigenvalues of Bi-drifted Laplacian on smooth metric measure spaces.

problem Eigenvalue problems for Bi-drifted Laplacian on compact manifolds with boundary conditions.
method Obtained lower bounds using specific curvature conditions.
result Lower bounds for the first eigenvalue of Bi-drifted Laplacian.

We introduce a flow of Kähler structures over Fano manifolds with formal limit at infinite time a Kähler-Ricci soliton. This flow correspond to a Perelman's modified backward Kähler-Ricci type flow that we call Soliton-Kähler-Ricci flow. It can be generated by the Soliton-Ricci flow. We assume that the Soliton-Ricci fl…

2012-03-16abs ↗pdf ↗

We introduce a flow of Riemannian metrics over compact manifolds with formal limit at infinite time a shrinking Ricci soliton. We call this flow the Soliton-Ricci flow. It correspond to a Perelman's modified backward Ricci type flow with some special restriction conditions. The restriction conditions are motivated by c…

2012-03-16abs ↗pdf ↗

We present a string inspired 3D Euclidean field theory as the starting point for a modified Ricci flow analysis of the Thurston conjecture. In addition to the metric, the theory contains a dilaton, an antisymmetric tensor field and a Maxwell-Chern Simons field. For constant dilaton, the theory appears to obey a Birkhof…

2003-06-27abs ↗pdf ↗

The paper studies modified Einstein tensors and their positivity properties on compact manifolds.

problem Analyzing the positivity of modified Einstein tensors and their implications on compact manifolds.
method Investigates modified Einstein tensors defined as $\Eink :=\Scal \, g -k\Ric$ for 0<k<n0<k<n and studies their positivity properties.
result Defines a smooth invariant $\cEin(M)$ measuring how far a manifold is from admitting an Einstein metric with positive scalar curvature.

Sharp gradient estimates for a weighted p-Laplacian equation on metric measure spaces.

problem Analyzing solutions to a specific weighted p-Laplacian equation.
method Applying Nash-Moser iteration to obtain sharp gradient estimates.
result Established Liouville theorems for the equation.

Study vanishing and splitting results on metric measure spaces with specific curvature bounds.

problem Analyzing vanishing and splitting properties on metric measure spaces with negative Bakry-Émery-Ricci curvature bounds.
method Examining various negative mm-Bakry-Émery-Ricci curvature lower bounds and first spectrum of the weighted Laplacian.
result Extensions and generalizations of existing results on vanishing and splitting properties.

Study lower bounds on modified K-energy on Fano manifolds with Kähler-Ricci solitons.

problem Lower boundedness of modified K-energy on Fano manifolds.
method Extend Tosatti's method to study Fano manifolds with Kähler-Ricci solitons.
result Establish lower bounds on modified K-energy for Kähler-Ricci solitons.

Modified Gibbs-Helmholtz equation geometric models for thermodynamics.

problem Geometric interpretation of Gibbs-Helmholtz equation in thermodynamics.
method Developed new holonomic and non-holonomic geometric models associated to Gibbs-Helmholtz equation.
result Characterized equivalence between Gibbs-Helmholtz entropy and other entropies.

The study characterizes spacetime and modified gravity models using projective curvature tensor.

problem Characterizing spacetime and modified gravity models with projective curvature tensor.
method Analyzing $f\left(R,G ight)$, $f\left(R,T ight)$, and $f\left(R,L_{m} ight)$-gravity models.
result Projectively flat perfect fluid spacetimes represent dark energy era and are locally isometric to Minkowski or de-Sitter spacetimes.

In this note, a modified Kähler-Ricci flow is introduced and studied. The main point is to show the flexibility of Kähler-Ricci flow and summarize some useful techniques.

2008-01-22abs ↗pdf ↗

We investigate the Kähler-Ricci flow modified by a holomorphic vector field. We find equivalent analytic criteria for the convergence of the flow to a Kähler-Ricci soliton. In addition, we relate the asymptotic behavior of the scalar curvature along the flow to the lower boundedness of the modified Mabuchi energy.

2008-09-05abs ↗pdf ↗

Let (N,g)(N,g) be an nn-dimensional complete Riemannian manifold with nonempty boundary $\pt N$. Assume that the Ricci curvature of NN has a negative lower bound Ric(n1)c2Ric\geq -(n-1)c^2 for some c>0c>0, and the mean curvature of the boundary $\pt N$ satisfies H(n1)c0>(n1)cH\geq (n-1)c_0>(n-1)c for some c0>c>0c_0>c>0. Then a known result (s…

2013-06-17abs ↗pdf ↗

The paper explores symmetries in Kähler manifolds using Ricci tensor properties.

problem Investigating symmetries in Kähler manifolds involving Ricci tensor.
method Analyzing properties of Kähler-Einstein spaces and their generalizations.
result Clarified the geometric role of holomorphic Ricci pseudosymmetry and established new criteria for Kähler manifolds to be Einstein.

The paper introduces and analyzes pseudo generalized Ricci-recurrent spacetimes in modified gravity.

problem Characterizing and analyzing pseudo generalized Ricci-recurrent spacetimes in modified gravity.
method Introducing and characterizing pseudo generalized Ricci-recurrent spacetimes, proving their properties, and studying their impact under modified gravity scenarios.
result Pseudo generalized Ricci-recurrent spacetimes represent specific spacetime types under modified gravity scenarios.

The paper studies geometric constants under modified Ricci flows with variable parameters.

problem Understanding geometric constants under variable coupling parameters in Ricci flows.
method Introduced modified Ricci flows with variable coefficients, derived evolution formulas, and proved monotonicity conditions.
result Conditions for maintaining monotonicity of geometric constants under modified Ricci flows.

Among other results, a compact almost Kähler manifold is proved to be Kähler if the Ricci tensor is semi-negative and its length coincides with that of the star Ricci tensor or if the Ricci tensor is semi-positive and its first order covariant derivatives are Hermitian. Moreover, it is shown that there are no compact a…

2003-04-07abs ↗pdf ↗

New classification of gradient steady Ricci solitons with vanishing D-tensor.

problem Classifying gradient steady Ricci solitons with specific properties.
method Extending Cao-Chen's work on Bach-flat gradient Ricci solitons, proving properties for DD-flat solitons.
result Any nn-dimensional complete noncompact gradient steady Ricci soliton with vanishing DD-tensor is either Ricci-flat or isometric to the Bryant soliton.

Study compares spectral properties of a specific tensor in geometry.

problem Comparing spectral properties of a specific tensor in geometry.
method Diameter and global weighted volume comparison with a positive lower bound on the NN-Bakry-Emery Ricci tensor.
result Established diameter and volume comparisons for tensors with positive lower bounds.

The Bakry-Emery tensor gives an analog of the Ricci tensor for a Riemannian manifold with a smooth measure. We show that some of the topological consequences of having a positive or nonnegative Ricci tensor are also valid for the Bakry-Emery tensor. We show that the Bakry-Emery tensor is nondecreasing under a Riemannia…

2002-11-04abs ↗pdf ↗

The Bakry-Émery-Ricci tensor is extended and comparison theorems are proven.

problem Extending the Bakry-Émery-Ricci tensor and proving comparison theorems.
method Generalizations of the drifted Laplacian and Bakry-Émery-Ricci tensor, mean curvature comparison theorem, Myers-type theorem, Cheeger-Gromoll splitting theorem.
result Proved a version of the mean curvature comparison theorem and its consequences.