Search results for "RIEMANN"

Local softening of information geometric indicators of chaos in statistical modeling in the presence of quantum-like considerations

2013

In a previous paper (C. Cafaro et al., 2012), we compared an uncorrelated 3D Gaussian statistical model to an uncorrelated 2D Gaussian statistical model obtained from the former model by introducing a constraint that resembles the quantum mechanical canonical minimum uncertainty relation. Analysis was completed by way of the information geometry and the entropic dynamics of each system. This analysis revealed that the chaoticity of the 2D Gaussian statistical model, quantified by means of the Information Geometric Entropy (IGE), is softened or weakened with respect to the chaoticity of the 3D Gaussian statistical model due to the accessibility of more information. In this companion work, we…

Equilibrium real gas computations using Marquina's scheme

2003

Marquina's approximate Riemann solver for the compressible Euler equations for gas dynamics is generalized to an arbitrary equilibrium equation of state. Applications of this solver to some test problems in one and two space dimensions show the desired accuracy and robustness

On fractional smoothness and Lp-approximation on the Wiener space

2015

Markovian Connection, Curvature and Weitzenböck Formula on Riemannian Path Spaces

2001

Abstract We shall consider on a Riemannian path space P m o ( M ) the Cruzeiro–Malliavin's Markovian connection. The Laplace operator will be defined as the divergence of the gradient. We shall compute explicitly the associated curvature tensor. A Weitzenbock formula will be established. To this end, we shall introduce an “inner product” between the tangent processes and simple vector fields.

Graded metrics adapted to splittings

1997

Homogeneous graded metrics over split ℤ2-graded manifolds whose Levi-Civita connection is adapted to a given splitting, in the sense recently introduced by Koszul, are completely described. A subclass of such is singled out by the vanishing of certain components of the graded curvature tensor, a condition that plays a role similar to the closedness of a graded symplectic form in graded symplectic geometry: It amounts to determining a graded metric by the data {g, ω, Δ′}, whereg is a metric tensor onM, ω 0 is a fibered nondegenerate skewsymmetric bilinear form on the Batchelor bundleE → M, and Δ′ is a connection onE satisfying Δ′ω = 0. Odd metrics are also studied under the same criterion an…

Geometry and “Metaphysics of Space” in Gauss and Riemann

1994

Gauss’s research on the principles of geometry and the axiom of parallels have been the subject of study for long time (e.g. Stackel 1933) which has shed light once and for all on his role in the early history of non-Euclidean geometry. It is therefore unnecessary to go through it all over again; what is more interesting here is to examine the development of Gauss’s ideas from another standpoint which emerges from the first testimony of his reflections on a subject that mathematicians had examined in vain right from antiquity: i.e. the possibility of proving the proposition that Euclid had taken as an axiom and formulated in the following terms: “That, if a straight line falling on two stra…

Afternotes on PHM: Harmonic ENO Methods

2003

PHM methods have been used successfully as reconstruction procedures to design high-order Riemann solvers for nonlinear scalar and systems of conservation laws, (see [8], [1], [4]). We introduce a new class of polynomial reconstruction procedures based on the harmonic mean of the absolute values of finite diferences used as difference-limiter, following the original idea used before to design the piecewise hyperbolic method, introduced in [8]. We call those methods ’harmonic ENO methods’, (HENO). Furthermore, we give analytical and numerical evidence of the good behavior of these methods used as reconstruction procedures for the numerical approximation by means of shock-capturing methods fo…

Homeomorphisms of finite distortion : from the unit ball to cusp domains in R^{3}

2016

Representation of solutions and large-time behavior for fully nonlocal diffusion equations

2017

Abstract We study the Cauchy problem for a nonlocal heat equation, which is of fractional order both in space and time. We prove four main theorems: (i) a representation formula for classical solutions, (ii) a quantitative decay rate at which the solution tends to the fundamental solution, (iii) optimal L 2 -decay of mild solutions in all dimensions, (iv) L 2 -decay of weak solutions via energy methods. The first result relies on a delicate analysis of the definition of classical solutions. After proving the representation formula we carefully analyze the integral representation to obtain the quantitative decay rates of (ii). Next we use Fourier analysis techniques to obtain the optimal dec…

Differentiability properties of the isoperimetric profile and topology of analytic Riemannian manifolds.

2009

Abstract: We show that smooth isoperimetric profiles are exceptional for real analytic Riemannian manifolds. For instance, under some extra assumptions, this can happen only on topological spheres