3,114 research outputs found
Some remarks on Huisken's monotonicity formula for mean curvature flow
We discuss a monotone quantity related to Huisken's monotonicity formula and
some technical consequences for mean curvature flow.Comment: in "Singularities in nonlinear evolution phenomena and applications",
157-169, CRM Series, 9, Ed. Sc. Norm. Pisa, 200
Evolution of the Weyl Tensor under the Ricci Flow
We compute the evolution equation of the Weyl tensor under the Ricci flow of
a Riemannian manifold and we discuss some consequences for the classification
of locally conformally flat Ricci solitons
A Flow Tangent to the Ricci Flow via Heat Kernels and Mass Transport
We present a new relation between the short time behavior of the heat flow,
the geometry of optimal transport and the Ricci flow. We also show how this
relation can be used to define an evolution of metrics on non-smooth metric
measure spaces with Ricci curvature bounded from below
Line profile analysis of the Delta Scuti star HD2724=BB Phe: mode identification and amplitude variations
The line profile variations of the Delta Scuti star HD 2724=BB Phe were
studied on the basis of new 189 high-resolution spectrograms covering 52 hours
of observations on a baseline of 8.3 days. By combining these results with
those of a previous campaign 13 pulsation modes were identified: 5 of them are
both photometric and spectroscopic, 3 are purely spectroscopic and 5 purely
photometric. For the first time it was possible to compare spectroscopic data
taken in two different seasons: 6 modes were found to be common to both
datasets and furthermore strong amplitude variations of the excited modes were
detected. The fit of the line profile variations with a model of non-radial
pulsating star allowed us to obtain a reasonable estimate of the inclination of
the rotational axis and to propose the l,m typing of the spectroscopic modes.
The frequency content resembles that of 4 CVn, a delta Sct star with similar
physical parameters.Comment: 7 pages (in A&A style), 5 ps figures (Fig. 4 in colour) Accepted for
A&A Main Journa
Hamilton-Jacobi Equations and Distance Functions on Riemannian Manifolds
The paper is concerned with the properties of the distance function from a
closed subset of a Riemannian manifold, with particular attention to the set of
singularities
Motion by curvature of networks with two triple junctions
We consider the evolution by curvature of a general embedded network with two
triple junctions. We classify the possible singularities and we discuss the
long time existence of the evolution
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