William Weiss
Professor and Chief University of Toronto, Department of Mathematics
- Toronto ON
William Weiss is a mathematics professor at University Of Toronto St George Campus.
University of Toronto, Department of Mathematics
View more experts managed by University of Toronto, Department of Mathematics
Industry Applications
Research Interests
Articles
Ergodicity of Markov processes via non-standard analysis
Probability2016
A time-homogeneous Markov process with a stationary probability distribution π will converge to π in an appropriate sense (i.e., will be “ergodic”), under suitable conditions (such as “irreducibility”). This phenomenon is well understood for processes in discrete time and space, and for processes in continuous time and discrete space (see e.g. [5]), and for processes in discrete time and continuous space. However, for processes in continuous time and space, there are apparently no such clean results; the closest are apparently the results in using awkward assumptions about skeleton chains (see Section 5 below)...
Variations on ω-boundedness
Israel Journal of Mathematics2013
Let be a property (or, equivalently, a class) of topological spaces. A space X is called-bounded if every subspace of X with (or in) has compact closure. Thus, countable-bounded has been known as ω-bounded and (σ-compact)-bounded as strongly ω- ...
Universal functions
arXiv2012
A function of two variables F (x, y) is universal iff for every other function G (x, y) there exists functions h (x) and k (y) with G (x, y)= F (h (x), k (y)) Sierpinski showed that assuming the continuum hypothesis there exists a Borel function F (x, y) which is universal ...
