Shock-Wave Solutions of the Einstein Equations with Perfect Fluid Sources: Existence and Consistency by a Locally Inertial Glimm Scheme

Shock-Wave Solutions of the Einstein Equations with Perfect Fluid Sources: Existence and Consistency by a Locally Inertial Glimm Scheme
Author: Jeff Groah
Publisher: American Mathematical Soc.
Total Pages: 98
Release: 2004
Genre: Mathematics
ISBN: 082183553X

Demonstrates the consistency of the Einstein equations at the level of shock-waves by proving the existence of shock wave solutions of the spherically symmetric Einstein equations for a perfect fluid, starting from initial density and velocity profiles that are only locally of bounded total variation.

Shock Wave Interactions in General Relativity

Shock Wave Interactions in General Relativity
Author: Jeffrey Groah
Publisher: Springer Science & Business Media
Total Pages: 157
Release: 2007-04-03
Genre: Mathematics
ISBN: 0387446028

This monograph presents a self contained mathematical treatment of the initial value problem for shock wave solutions of the Einstein equations in General Relativity. It has a clearly outlined goal: proving a certain local existence theorem. Concluding remarks are added and commentary is provided throughout. The author is a well regarded expert in this area.

Hyperbolic Problems: Theory, Numerics, Applications

Hyperbolic Problems: Theory, Numerics, Applications
Author: Sylvie Benzoni-Gavage
Publisher: Springer Science & Business Media
Total Pages: 1117
Release: 2008-01-12
Genre: Mathematics
ISBN: 3540757120

This volume contains papers that were presented at HYP2006, the eleventh international Conference on Hyperbolic Problems: Theory, Numerics and Applications. This biennial series of conferences has become one of the most important international events in Applied Mathematics. As computers became more and more powerful, the interplay between theory, modeling, and numerical algorithms gained considerable impact, and the scope of HYP conferences expanded accordingly.

Holder Continuity of Weak Solutions to Subelliptic Equations with Rough Coefficients

Holder Continuity of Weak Solutions to Subelliptic Equations with Rough Coefficients
Author: Eric T. Sawyer
Publisher: American Mathematical Soc.
Total Pages: 176
Release: 2006
Genre: Mathematics
ISBN: 0821838261

This mathematical monograph is a study of interior regularity of weak solutions of second order linear divergence form equations with degenerate ellipticity and rough coefficients. The authors show that solutions of large classes of subelliptic equations with bounded measurable coefficients are H lder continuous. They present two types of results f

Stability of Spherically Symmetric Wave Maps

Stability of Spherically Symmetric Wave Maps
Author: Joachim Krieger
Publisher: American Mathematical Soc.
Total Pages: 96
Release: 2006
Genre: Mathematics
ISBN: 0821838776

Presents a study of Wave Maps from ${\mathbf{R}}^{2+1}$ to the hyperbolic plane ${\mathbf{H}}^{2}$ with smooth compactly supported initial data which are close to smooth spherically symmetric initial data with respect to some $H^{1+\mu}$, $\mu>0$.

Tangential Boundary Stabilization of Navier-Stokes Equations

Tangential Boundary Stabilization of Navier-Stokes Equations
Author: Viorel Barbu
Publisher: American Mathematical Soc.
Total Pages: 146
Release: 2006
Genre: Mathematics
ISBN: 0821838741

In order to inject dissipation as to force local exponential stabilization of the steady-state solutions, an Optimal Control Problem (OCP) with a quadratic cost functional over an infinite time-horizon is introduced for the linearized N-S equations. As a result, the same Riccati-based, optimal boundary feedback controller which is obtained in the linearized OCP is then selected and implemented also on the full N-S system. For $d=3$, the OCP falls definitely outside the boundaries of established optimal control theory for parabolic systems with boundary controls, in that the combined index of unboundedness--between the unboundedness of the boundary control operator and the unboundedness of the penalization or observation operator--is strictly larger than $\tfrac{3}{2}$, as expressed in terms of fractional powers of the free-dynamics operator. In contrast, established (and rich) optimal control theory [L-T.2] of boundary control parabolic problems and corresponding algebraic Riccati theory requires a combined index of unboundedness strictly less than 1. An additional preliminary serious difficulty to overcome lies at the outset of the program, in establishing that the present highly non-standard OCP--with the aforementioned high level of unboundedness in control and observation operators and subject, moreover, to the additional constraint that the controllers be pointwise tangential--be non-empty; that is, it satisfies the so-called Finite Cost Condition [L-T.2].

The Complex Monge-Ampere Equation and Pluripotential Theory

The Complex Monge-Ampere Equation and Pluripotential Theory
Author: Sławomir Kołodziej
Publisher: American Mathematical Soc.
Total Pages: 82
Release: 2005
Genre: Mathematics
ISBN: 082183763X

We collect here results on the existence and stability of weak solutions of complex Monge-Ampere equation proved by applying pluripotential theory methods and obtained in past three decades. First we set the stage introducing basic concepts and theorems of pluripotential theory. Then the Dirichlet problem for the complex Monge-Ampere equation is studied. The main goal is to give possibly detailed description of the nonnegative Borel measures which on the right hand side of the equation give rise to plurisubharmonic solutions satisfying additional requirements such as continuity, boundedness or some weaker ones. In the last part, the methods of pluripotential theory are implemented to prove the existence and stability of weak solutions of the complex Monge-Ampere equation on compact Kahler manifolds. This is a generalization of the Calabi-Yau theorem.