Conveners
Poster session
- Alessandra R Brazzale (University of Padova)
- Sabino Matarrese (University of Padova - DFA)
The computational cost of individual likelihood evaluations and physics simulations is a key limiting factor for BSM global fits and other large-scale parameter scans. One approach to tackle this is to use fast, pretrained emulators for the most expensive computations. However, as the set of relevant experimental results is frequently updated, many pretrained emulators have limited...
Satellite conjunctions involving “near misses” of space objects are becoming increasingly likely. One approach to risk analysis for them involves the computation of the collision probability, but this has been regarded as having some counterintuitive properties and its interpretation has been debated. We propose a new approach based on a simple statistical model and discusses inference on the...
In extreme value theory, the dependence structure between multivariate exceedances over a high threshold is fully characterised by their projections on the unit simplex. Under mild conditions, the only constraint on these angular variables is that their marginal means are equal. Their distribution functions thus form a non-parametric class within which deriving flexible and easy to use models...
Searching for as yet undetected γ-ray sources is a major target of the Fermi LAT Collaboration. We address the problem by clustering the directions of the high-energy photon emissions detected by the telescope onboard the Fermi spacecraft. Putative sources are identified as the excess mass of disconnected high density regions on a sphere mesh, which allows for their joint discrimination from...
Abstract: Nowadays, approximate Bayesian methods, such as integrated nested Laplace approximation, variational Bayes, expectation propagation and stochastic variational inference, are routinely used in statistics for the estimation of complex hierarchical models. They are particularly convenient, if not necessary, when Markov chain Monte Carlo algorithms can not be employed due to memory or...
The Block Maxima and Peaks over a Threshold (POT) methods are the most popular statistical procedures used to analyse univariate extremes by means of the Generalised Extreme Value (GEV) and Generalised Pareto (GP) distributions, respectively. Exploiting the three-parameters GEV family of distributions as an asymptotic approximation for the underlying data distribution when this is computed for...
Searching for as yet undetected γ-ray sources is a major target of the Fermi LAT Collaboration. This type of high-energy photon emission typically presents itself as a highly concentrated point-like spot in the whole sky map, which blends in with the irregularly shaped background emission spread over the entire area. The identification of high-energy emitting sources is a fundamental task to...
In Bayesian statistics, deterministic approximations of the posterior distribution are often the preferred choice in the case of complex models, mainly for computational reasons. A common drawback of many of these approximations is that they usually belong to the Gaussian family and, therefore, can miss important characteristics of the posterior such as asymmetry. To alleviate this issue, this...
