Is there an appropriate place for asking mathematical IP questions? Another mailing list?
An option that I���ve explored in the past is to ask questions about imprecise probability on mathematics the question-and-answer site
math.stackexchange.com, but so far this doesn���t seem to be a site in which people knowledgeable about IP participate. (Questions on math.stackexchange are classified by ���tags���. There is so little interest
in IP that I���ve found no tags representing any aspect of it.)
stats.stackexchange.com is another option, but that���s focused on statistics, and not all IP questions are statistics-related.
mathoverflow.net
is part of the same family of sites, but it���s "a question and answer site for professional mathematicians.��� (Whatever that term means, it would not apply to me.)
Thanks very much-
Marshall
[In case it���s helpful, to illustrate the level of question I want to be able ask, here is the question with which I���m currently struggling: I���m reading Hermans and Skulj���s ���Stochastic processes��� chapter of of Introduction to Imprecise
Probabilities, and I���m puzzled by the novel (to me) definition of ���transition operator��� in 11.3. I understand that it���s intended as a sort of generalization of the standard Markov process transition operator concept, but there���s something I���m just not
seeing due to lack of experience, lack of insight, etc.: As I understand definition 11.3, T_n f(x) is essentially a conditional expectation���i.e., in traditional notation: E( f | X_n = x). How is it that T_n can operate on f(x) and ���see��� what x is? Either
I must take 11.3 to imply that the domain of T_n consists of the range of f, or that the domain of T_n consists of gambles f in L(X_n). Either way, x does not seem to appear as an argument to T_n; it seems to ���know��� nothing about x. If the first interpretation
were correct, then if f was not one-to-one, f(x) could equal f(y) where x != y, and I see no reason to assume that E(f | X_n=x) must always equal E(f | X_n=y). I���m not sure if I���m making myself clear; I���m sure that there���s something I've overlooked, or that
I���m misinterpreting some notation or concept.]
Marshall Abrams, Associate Professor
Department of Philosophy, University of Alabama at Birmingham
Mail: HB 414A, 900 13th Street South, Birmingham, AL 35294-1260; Office: HB 418