Concept

Geodesics in general relativity

Publications associées (33)

Discontinuous Galerkin method for computing gravitational waveforms from extreme mass ratio binaries

Gravitational wave emission from extreme mass ratio binaries (EMRBs) should be detectable by the joint NASA-ESA LISA project, spurring interest in analytical and numerical methods for investigating EMRBs. We describe a discontinuous Galerkin (dG) method fo ...

IOP PUBLISHING LTD2009

Geodesic flows on semidirect-product Lie groups: geometry of singular measure-valued solutions

Cesare Tronci

The EPDiff equation (or dispersionless Camassa-Holm equation in 1D) is a well known example of geodesic motion on the Diff group of smooth invertible maps (diffeomorphisms). Its recent two-component extension governs geodesic motion on the semidirect produ ...

2009

Totally geodesic subgraphs of the pants complex

Hugo Parlier

In recent work of Brock's, the pants graph is shown to be a combinatorial model for the completion of the Weil-Petersson metric on Teichmuller space. We prove that every Farey graph embedded in the pants graph is totally geodesic, in analogy with the extri ...

2008

On the estimation of geodesic paths on sampled manifolds after random projections

Pierre Vandergheynst, Matteo Sorci

In this paper, we focus on the use of random projections as a dimensionality reduction tool for sampled manifolds in high-dimensional Euclidean spaces. We show that geodesic paths approximations from nearest neighbors Euclidean distances are well-preserved ...

2008

Multiplicities of simple closed geodesics and hypersurfaces in Teichmuller space

Hugo Parlier

Using geodesic length functions, we define a natural family of real codimension 1 subvarieties of Teichmuller space, namely the subsets where the lengths of two distinct simple closed geodesics are of equal length. We investigate the point set topology of ...

2008

On the geometry of simple closed geodesics

Hugo Parlier

The leitmotif of this dissertation is the search for length formulas and sharp constants in relation with simple closed geodesics on hyperbolic compact Riemann surfaces. The main tools used are those of hyperbolic trigonometry, topological properties of si ...

EPFL2004

Optimal control of geodesics in Riemannian manifolds

Klaus-Dieter Semmler, Roland Rozsnyo

Summary: We present a method based on an optimal control technique for numerical computations of geodesic paths between two fixed points of a Riemannian manifold under the assumption of existence. In this method, the control variable is the tangent vector ...

2004

Topological defects and gravity in theories with extra dimensions

Ewald Rössl

Recent proposals of large and infinite extra dimensions triggered a strong research activity in theories in which our universe is considered as a sub-manifold of some higher-dimensional space-time, a so-called 3-brane. In this context, it is generally assu ...

EPFL2004

Transplanckian collisions at the LHC and beyond

Riccardo Rattazzi

Elastic collisions in the transplanckian region, where the center-of-mass energy is much larger than the fundamental gravity mass scale, can be described by linearized general relativity and known quantum-mechanical effects as long as the momentum transfer ...

2002

Effect of toroidal current and profile on ballooning instability mechanisms in a quasiaxisymmetric stellarator

Wilfred Anthony Cooper

Finite toroidal plasma current reduces the magnitude of the normal magnetic field line curvature near midvolume in a quasiaxisymmetric stellarator. This improves the ideal ballooning stability conditions. Near the edge of the plasma, a hollow toroidal curr ...

2001

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