Dissertation/Thesis Abstract

Bayesian Inference in Gaussian Graphical Models When the Underlying Graph is Non-Decomposable
by Saha, Abhishek, Ph.D., University of Florida, 2016, 82; 10679173
Abstract (Summary)

In recent statistical literature Bayesian inference for graphical models has received much attention. It is well known that when the graph G is decomposable, Bayesian inference is significantly more tractable than in the general non-decomposable setting. Penalized likelihood inference on the other hand has made tremendous gains in the past few years in terms of scalability and tractability. Bayesian inference, however, has not had the same level of success, though a scalable Bayesian approach has its respective strengths, especially in terms of quantifying uncertainty. To address this gap, we propose a scalable and exible novel Bayesian approach for estimation and model selection in Gaussian undirected graphical models. We first develop a class of generalized G-Wishart distributions with multiple shape parameters for an arbitrary underlying graph. This class contains the G-Wishart distribution as a special case. We then introduce the class of Generalized Bartlett (GB) graphs, and derive an efficient Gibbs sampling algorithm to obtain posterior draws from generalized G-Wishart distributions corresponding to a GB graph. The class of Generalized Bartlett graphs contains the class of decomposable graphs as a special case, but is substantially larger than the class of decomposable graphs. We proceed to derive theoretical properties of the proposed Gibbs sampler. We then demonstrate that the proposed Gibbs sampler is scalable to significantly higher dimensional problems as compared to using an accept-reject or a Metropolis-Hasting algorithm. Finally, we show the efficacy of the proposed approach on simulated and real data.

Indexing (document details)
Advisor: Khare, Kshitij
Commitee: Banerjee, Arunava, Ghosh, Malay, Hobert, Jim
School: University of Florida
Department: Statistics
School Location: United States -- Florida
Source: DAI-B 79/04(E), Dissertation Abstracts International
Subjects: Statistics
Keywords: Gibbs sampling, Non decomposable graphs
Publication Number: 10679173
ISBN: 978-0-355-40193-6
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