Partial Differential Equations Seminar
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Mon, 27/04/2009 17:00 |
Michele Bartuccelli (University of Surrey) |
Partial Differential Equations Seminar  |
Gibson 1st Floor SR |
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Mon, 04/05/2009 17:00 |
Marc Briane (INSA Rennes & Université Rennes 1) |
Partial Differential Equations Seminar |
Gibson 1st Floor SR |
This work in collaboration
with J. Casado-Díaz deals with the asymptotic behaviour of
two-dimensional linear conduction problems for which the sequence of
conductivity matrices is bounded from below but not necessarily from
above.
On the one hand, we prove an extension in dimension two of the
classical div-curl lemma, which allows us to derive a H-convergence
type result for any L1-bounded sequence of conductivity matrices.
On the other hand, we obtain a uniform convergence result satisfied
by the minimisers of a sequence of two-dimensional diffusion
energies. This implies the closure for the L2-strong topology of
 -convergence of the sets of equicoercive diffusion energies
without assuming any bound from above. A few counter-examples in
dimension three, connected with the appearance of non-local effects,
show the specificity of dimension two in the two previous compactness
results. |
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Mon, 11/05/2009 17:00 |
Jian-Guo Liu (College Park, Maryland) |
Partial Differential Equations Seminar |
Gibson 1st Floor SR |
| For incompressible Navier-Stokes equations in a bounded domain, I will first present a formula for the pressure that involves the commutator of the Laplacian and Leray-Helmholtz projection operators. This commutator and hence the pressure is strictly dominated by the viscous term at leading order. This leads to a well-posed and computationally congenial unconstrained formulation for the Navier-Stokes equations. Based on this pressure formulation, we will present a new understanding and design principle for third-order stable projection methods. Finally, we will discuss the delicate inf-sup stability issue for these classes of methods. This is joint work with Bob Pego and Jie Liu. | |||
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Mon, 18/05/2009 17:00 |
Louis Nirenberg (Courant Institute) |
Partial Differential Equations Seminar |
Gibson 1st Floor SR |
| Some results of R.Harvey and B.Lawson on the Dirichlet problem for a class of fully nonlinear elliptic equations will be presented. No background is required; the talk will be expository. | |||
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Mon, 08/06/2009 17:00 |
Jan Kristensen (Oxford) |
Partial Differential Equations Seminar |
Gibson 1st Floor SR |
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Mon, 15/06/2009 17:00 |
Herbert Amann (University of Zurich) |
Partial Differential Equations Seminar |
Gibson 1st Floor SR |
