We continue the exposition on self-genericity axioms for ideals on P(Z) (Club Catch, Projective Catch and Stationary Catch). We establish some relations with forcing axioms and with the existence of certain regular forcing embeddings, and also point out connections with Precipitousness. In particular we observe that if Projective Catch holds for an ideal, then that ideal is precipitous, and the converse holds for ideals that concentrate on countable sets. Finally we give an overview of the method used for proving the existence of models with Woodin cardinals coming from these axioms, using the Core Model Theory.
Two very different mathematical topics, where one comes from the social sciences and the other from the physical sciences. It is easy to expect that they have nothing to do with one another. Instead, and as it will be developed in this talk, thanks to connecting power of mathematics, they share several relationships.
We continue the exposition on self-genericity axioms for ideals on P(Z) (Club Catch, Projective Catch and Stationary Catch). We establish some relations with forcing axioms and with the existence of certain regular forcing embeddings, and also point out connections with Precipitousness. In particular we observe that if Projective Catch holds for an ideal, then that ideal is precipitous, and the converse holds for ideals that concentrate on countable sets. Finally we give an overview of the method used for proving the existence of models with Woodin cardinals coming from these axioms, using the Core Model Theory.
In this talk, I will discuss recent results on the
large time well-posedness of classical solutions to the
multi-dimensional compressible Navier-Stokes system with possible
large oscillations and vacuum.
The focus will be on finite-time blow-up of classical solutions for
the 3-D full compressible Navier-Stokes system, and the global
existence of classical solutions to the isentropic compressible
Navier-Stokes system in both 2-D and 3-D in the presence of vacuum
and possible large oscillations. New estimates on the fast decay
of the pressure in the presence of vacuum will be presented, which
are crucial for the well-posedness theory in 2-dimensional case.
In this talk, I will discuss recent results on the
large time well-posedness of classical solutions to the
multi-dimensional compressible Navier-Stokes system with possible
large oscillations and vacuum.
The focus will be on finite-time blow-up of classical solutions for
the 3-D full compressible Navier-Stokes system, and the global
existence of classical solutions to the isentropic compressible
Navier-Stokes system in both 2-D and 3-D in the presence of vacuum
and possible large oscillations. New estimates on the fast decay
of the pressure in the presence of vacuum will be presented, which
are crucial for the well-posedness theory in 2-dimensional case.
We introduce a new multiscale Gaussian beam method for the
numerical solution of the wave equation with smooth variable
coefficients. The first computational question addressed in this
paper is how to generate a Gaussian beam representation from general
initial conditions for the wave equation. We propose fast multiscale
Gaussian wavepacket transforms and introduce a highly efficient
algorithm for generating the multiscale beam representation for a
general initial condition. Starting from this multiscale
decomposition of initial data, we propose the multiscale Gaussian
beam method for solving the wave equation. The second question is
how to perform long time propagation. Based on this new
initialization algorithm, we utilize a simple reinitialization
procedure that regenerates the beam representation when the beams
become too wide. Numerical results in one, two, and three dimensions
illustrate the properties of the proposed algorithm. The methodology
can be readily generalized to treat other wave propagation problems.
Contrary to their classical namesakes over the ring of integers, Pell equations over function rings in characteristic zero need not have infinitely many solutions. How often this occurs has been the theme of recent work of D. Masser and U. Zannier. The case of smooth curves is governed by the relative Manin-Mumford conjecture on abelian schemes. We pursue this study by considering singular curves and the associated generalized jacobians.
Congratulations to Chancellor's Professor John Lowengrub on being named the SIAM Julian Cole Lecturer for 2014! John was recognized for "seminal contributions to fluid dynamics, materials science, and computational biology through the development of mathematical models, computation methods, and numerical simulations of free-boundary problems and tumor growth." This award is given every four years for an outstanding contribution to the mathematical characterization and solution of a challenging problem in the physical or biological sciences, or in engineering.