computational statistics and molecular simulation [18w5023]

This X fertilisation workshop Gabriel Stolz, Luke Bornn and myself organised towards reinforcing the interface between molecular dynamics and Monte Carlo statistical methods has now started! At the casa matematicà Oaxaca, the Mexican campus of BIRS, which is currently housed by a very nice hotel on the heights of Oaxaca. And after a fairly long flight for a large proportion of the participants. On the first day, Arthur Voter gave a fantastic “hand-on” review of molecular dynamics for material sciences, which was aimed at the statistician side of the audience and most helpful in my own understanding of the concepts and techniques at the source of HMC and PDMP algorithms. (Although I could not avoid a few mini dozes induced by jetlag.) Including the BAOAB version of HMC, which sounded to me like an improvement to investigate. The part on metastability, completed by a talk by Florian Maire, remained a wee bit mysterious [to me].

The shorter talks of the day all brought new perspectives and information to me (although they were definitely more oriented towards their “own” side of the audience than the hand-on lecture). For instance, Jesús María Sanz-Serna gave a wide ranging overview of numerical integrators and Tony Lelièvre presented a recent work on simulating measures supported by manifolds via an HMC technique constantly projecting over the manifold, with proper validation. (I had struggled with the paper this summer and this talk helped a lot.) There was a talk by Josh Fash on simulating implicit solvent models that mixed high-level programming and reversible jump MCMC, with an earlier talk by Yong Chen on variable dimension hidden Markov models that could have also alluded to reversible jump. Angela Bito talked about using ASIS (Ancillarity-sufficiency interweaving strategy) for improving the dynamics of an MCMC sampler associated with a spike & slab prior, the recentering-decentering cycle being always a sort of mystery to me [as to why it works better despite introducing multimodality in this case], and Gael Martin presented some new results on her on-going work with David Frazier about approximate Bayes with misspecified models, with the summary statistic being a score function that relates the work to the likelihood free approach of Bissiri et al.