27,003 research outputs found
Wilson surfaces and higher dimensional knot invariants
An observable for nonabelian, higher-dimensional forms is introduced, its
properties are discussed and its expectation value in BF theory is described.
This is shown to produce potential and genuine invariants of higher-dimensional
knots.Comment: 31 pages, 9 figure
On the isomorphism between the reduction algebra and the invariant differential operators on Lie groups
Using techniques of deformation (bi)quantization we establish a non-canonical
algebra isomorphism between the deformed reduction algebra and the invariant
differential operators on G/H. Further results concerning other deformations of
these two algebras are also proved. Part of the author's PhD thesis at
University Paris 7, 2009.Comment: 27 page
The Degree of the Tangent and Secant Variety to a Projective Surface
In this paper we present a way of computing the degree of the secant (resp.,
tangent) variety of a smooth projective surface, under the assumption that the
divisor giving the embedding in the projective space is -very ample. This
method exploits the link between these varieties and the Hilbert scheme
-dimensional subschemes of length of the surface.Comment: 20 pages; generalization of the previous version (from projective K3
surfaces to any projective surface) and improvement of the expositio
Conditional probability estimation
This paper studies in particular an aspect of the estimation of conditional probability distributions by maximum likelihood that seems to have been overlooked in the literature on Bayesian networks: The information conveyed by the conditioning event should be included in the likelihood function as well
Empirical interpretation of imprecise probabilities
This paper investigates the possibility of a frequentist interpretation of imprecise probabilities, by generalizing the approach of Bernoulli’s Ars Conjectandi. That is, by studying, in the case of games of chance, under which assumptions imprecise probabilities can be satisfactorily estimated from data. In fact, estimability on the basis of finite amounts of data is a necessary condition for imprecise probabilities in order to have a clear empirical meaning. Unfortunately, imprecise probabilities can be estimated arbitrarily well from data only in very limited settings
- …