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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.

168,742 papers · 148 categories

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48 results for Modified Ricci curvature

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 sets up eigenvalue comparison theorems for specific Laplacians on manifolds.

problem Eigenvalue comparison theorems for Witten-Laplacian and weighted pp-Laplacian on manifolds with modified Ricci curvature.
method Established Cheng-type eigenvalue comparison theorems for the first Dirichlet eigenvalues of the Witten-Laplacian and weighted pp-Laplacian on geodesic balls.
result Successfully set up eigenvalue comparison theorems for the Witten-Laplacian and weighted pp-Laplacian.

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 ↗

We define the Ricci curvature on simplicial complexes by modifying the definition of the Ricci curvature on graphs, and we prove the upper and lower bounds of the Ricci curvature. These properties are generalizations of previous studies. Moreover, we obtain an estimate of the eigenvalues of the Laplacian on simplicial …

2019-06-18abs ↗pdf ↗

Proves volume comparison and monotonicity for Bakry-Émery Ricci curvature.

problem Volume comparison and monotonicity for Bakry-Émery Ricci curvature.
method Relative volume comparison theorem for LPL^P-bound of Bakry-Émery Ricci curvature and gradient of potential function.
result Modified proof for volume comparison and monotonicity of Kähler-Ricci flow.

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.

Following work of Ecker, we consider a weighted Gibbons-Hawking-York functional on a Riemannian manifold-with-boundary. We compute its variational properties and its time derivative under Perelman's modified Ricci flow. The answer has a boundary term which involves an extension of Hamilton's Harnack expression for the …

2011-05-30abs ↗pdf ↗

The study proves inequalities and curvature properties for Markov chains.

problem Isoperimetric and concentration inequalities for Markov chains.
method Laplacian separation principle for eikonal equation; modified log-Sobolev constant; Ollivier curvature.
result Affirmative answers to open questions and new inequalities.

We study a modified notion of Ollivier's coarse Ricci curvature on graphs introduced by Lin, Lu, and Yau in [11]. We establish a rigidity theorem for complete graphs that shows a connected finite simple graph is complete if and only if the Ricci curvature is strictly greater than one. We then derive explicit Ricci curv…

2019-07-15abs ↗pdf ↗

On a Riemannian metric-measure space, we establish an Alexandrov-Bakelman-Pucci type measure estimate connecting Bakry-Émery Ricci curvature lower bound, modified Laplacian and the measure of certain special sets. We apply this estimate to prove Harnack inequalities for the modified Laplacian operator and fully non-lin…

2011-02-28abs ↗pdf ↗

We construct new homogeneous Einstein spaces with negative Ricci curvature in two ways: First, we give a method for classifying and constructing a class of rank one Einstein solvmanifolds whose derived algebras are two-step nilpotent. As an application, we describe an explicit continuous family of ten-dimensional Einst…

1999-08-17abs ↗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 ↗

The paper studies mean curvature flow in a Ricci flow background with extended Ricci flow.

problem Analyzing mean curvature flow in a Ricci flow background.
method Computing variational properties and deriving evolution equations for mean curvature and second fundamental form.
result Established a Huisken's monotonicity-type formula for mean curvature solitons in an extended Ricci flow.

Study on generalized mm-Kropina metrics in modified gravity and cosmology.

problem Understanding the geometric properties and applications of generalized mm-Kropina metrics.
method Proving the rationality of Finslerian geometric objects and studying the conditions for Einstein metrics.
result Conditions for a generalized mm-Kropina metric to be an exact solution in modified gravity and cosmology.

We consider Ricci flow on a closed surface with cone points. The main result is: given a (nonsmooth) cone metric g_0 over a closed surface there is a smooth Ricci flow g(t) defined for (0,T], with curvature unbounded above, such that g(t) tends to g_0 as t tends to 0. This result means that Ricci flow provides a way fo…

2011-09-26abs ↗pdf ↗

Ricci-Filtration enhances retrieval-augmented generation rerankers for query-answer tasks by using discrete Ricci flow on graphs.

problem Improving retrieval-augmented generation rerankers for query-answer tasks.
method Discrete Ricci flow on graphs to evaluate structural importance of chunks.
result Ricci-Filtration outperforms baseline methods in accuracy, precision, recall, and F1 scores.

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.

We provide estimates on the Bartnik mass of constant mean curvature (CMC) surfaces which are diffeomorphic to spheres and have positive mean curvature. We prove that the Bartnik mass is bounded from above by the Hawking mass and a new notion we call the asphericity mass. The asphericity mass is defined by applying Hami…

2014-08-23abs ↗pdf ↗

We consider the evolution of the asymptotically hyperbolic mass under the curvature-normalized Ricci flow of asymptotically hyperbolic, conformally compactifiable manifolds. In contrast to asymptotically flat manifolds, for which ADM mass is constant during Ricci flow, we show that the mass of an asymptotically hyperbo…

2011-10-04abs ↗pdf ↗

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 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 ↗

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.

The article introduces pseudo generalized Ricci-recurrent spacetimes and their applications in modified gravity.

problem Characterizing and understanding pseudo generalized Ricci-recurrent spacetimes.
method Introduced and characterized pseudo generalized Ricci-recurrent spacetimes, provided examples, and studied their implications in modified gravity.
result Pseudo generalized Ricci-recurrent spacetimes represent perfect fluid spacetimes and can model dark energy epochs or static spacetimes.

We introduce a variation of the classical Ricci flow equation that modifies the unit volume constraint of that equation to a scalar curvature constraint. The resulting equations are named the Conformal Ricci Flow Equations because of the role that conformal geometry plays in constraining the scalar curvature. These equ…

2003-12-31abs ↗pdf ↗

Note shows equivalence of recent NEC reformulation to classical NEC for C2C^2-metrics.

problem Consistency of null energy condition in Lorentzian length spaces.
method Shows equivalence of recent reformulation of null energy condition to classical formulation for C2C^2-metrics.
result Equivalence of recent reformulation of null energy condition to classical formulation for C2C^2-metrics.

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.

The Milnor Problem (modified) in the theory of group growth asks whether any finite presented group of vanishing algebraic entropy has at most polynomial growth. We show that a positive answer to the Milnor Problem (modified) is equivalent to the Nilpotency Conjecture in Riemannian geometry: given n,d>0n, d>0, there exist…

2018-06-07abs ↗pdf ↗

We show that the coercivity of the modified Ding functional leads to the existence of a certain kind of balanced metrics and their convergence to the Kähler-Ricci soliton modulo automorphisms. In our results, we do not assume that the vanishing of the higher order modified Futaki invariants introduced by Berman-Nyström…

2015-03-19abs ↗pdf ↗

We introduce a modified non-linear heat equation tu=Δu+Γu\partial_t u = Δu + Γu as a substitute of logPtf\log P_t f where PtP_t is the heat semigroup. We prove an exponential decay of ΓuΓu under the Bakry Emery curvature condition CD(K,)CD(K,\infty) and prove the Li-Yau inequality Δutn2t-Δu_t \leq \frac{n}{2t} under the Bakry Emery curv…

2019-09-23abs ↗pdf ↗

The paper characterizes Whitney and contact Whitney spheres in complex and Sasakian space forms.

problem Characterizing spheres in complex and Sasakian space forms.
method Establishing optimal integral inequalities involving Ricci curvature and second fundamental form norms.
result New characterizations of Whitney and contact Whitney spheres in complex and Sasakian space forms.

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.