For singular operators of the form (H_{\alpha,\theta}u)_n=u_{n+1}+u_{n-1}+
\frac{g(\theta+n\alpha)}{f(\theta+n\alpha)} u_n, we prove such operators
have purely singular continuous spectrum on the set
{E: \delta{(\alpha,\theta)}>L(E)\}, where f and g are both analytic functions
on T.
The growth-optimal (Kelly) criterion almost surely leads to more capital in the long run and reaches levels of capital asymptotically faster than alternative strategies, but such outperformance may not be realized with high probability for an exceptionally long time. We will first demonstrate how the Kelly criterion arises in finance without first appealing to a logarithmic utility function, and then consider strategies based on alternative utilities that emphasize the probability of exceeding an underperforming benchmark faster than Kelly.
I will discuss a Kuranishi-type theorem for deformations of complex structure on ALE Kahler surfaces, which will be used to prove that for any scalar-flat Kahler ALE surface, all small deformations of complex structure also admit scalar-flat Kahler ALE metrics. A local moduli space of scalar-flat Kahler ALE metrics can then be constructed, which is universal up to small diffeomorphisms. I will also discuss a formula for the dimension of the local moduli space in the case of a scalar-flat Kahler ALE surface which deforms to a minimal resolution of an isolated quotient singularity. This is joint work with Jiyuan Han.
In 1950's Sierpinski asked whether there exists a linear order X isomorphic to its lexicographicaly ordered cube but not to its square. We will give some historical context and begin the proof that the answer is negative. More generally, if X is isomorphic to any of its finite powers X^n (n>1) then X is isomorphic to all of them.
I will talk about the construction of Kahler-Einstein metric under the assumption of negative holomorphic sectional curvature. This is based on the joint work with Yau.
We explore the structure of the singularities of Yang-Mills flow in dimensions n ≥ 4. First we derive a description of the singular set in terms of concentration for a localized entropy quantity, which leads to an estimate of its Hausdorff dimension. We develop a theory of tangent measures for the flow at such singular points, which leads to a stratification of the singular set. By a refined blowup analysis we obtain Yang-Mills connections or solitons as blowup limits at any point in the singular set. This is joint work with Jeffrey Streets
In this talk We discuss the Martin compactification of a special complete noncompact
surface with negative Gaussian curvature which arises in our study of infinitesimal
rigidity of three-dimensional (collapsed) steady gradient Ricci solitons. In
particular, we investigate positive eigenfunctions with eigenvalue one of the
Laplace operator and prove a uniqueness result: such eigenfunctions are unique up to
a positive constant multiple if certain boundary behavior is satisfied. This
uniqueness result was used to prove an infinitesimal rigidity theorem for
deformations of certain three-dimensional collapsed gradient steady Ricci soliton
with a non-trivial Killing vector field. It is a joint work with Huai-Dong Cao.