Events - Page 9

Prior to his appointment at Victoria University of Wellington in February 2015, Budhi had spent nearly three years at Bank of America Corp. working as a Quant at the level of AVP. He was based mainly in Singapore with direct reporting line to the Head of Quantitative Risk Management Group at BofA HQ in Charlotte, North Carolina. He joined BofA soon after the completion of his PhD in Utrecht in January 2007. His area of research is predominantly on applied probability and stochastic systems towards applications in actuarial science, financial stochastics, optimal stopping and free-boundary problems in theoretical and applied finance, stochastic filtering and smoothing, estimation of Markov chains with covariates dependent transition intensity matrix and their general mixtures, maximum likelihood recursive estimation under incomplete information. He was a visiting scholar, among others, to NYU Stern in April-May 2025, September 2019; Mathematical Institute, University of Copenhagen in February 2020, IEOR Department of Columbia University in May 2014, DAAD visiting scholar to Mathematical Institute of Goethe University of Frankfurt in October-November 2013.

Doctoral candidate Emilie Mai Elkiær at the Department of Mathematics will be defending the thesis Rigidity and amenability of locally compact groups via their actions on Lp-spaces for the degree of Philosophiae Doctor.

Carolina Euan is a Lecturer in Statistics at the Mathematics and Statistics Department, University of Lancaster. Her research interests include the development of new statistical methods for the analysis of complex time series and Spatio-temporal data. She has experience working with data analysis of ocean wave data, precipitation and drought events, and statistical models for particular matter concentrations.

In this talk, I will present a joint work with Matilde Manzaroli. I will introduce real tori (in the greater generality) as well as real equivariant torus embeddings. Then I will describe the structure of the torus orbits. It will allow us to easily compute the Betti numbers of the real loci of smooth real equivariant torus embeddings, provided that those real loci are compact. Then I will present a canonical "foliation" of their real loci by equivariant embeddings of split tori. I will express a necessary and sufficient condition for this foliation to be given by the fibre of a fibre bundle, and explain how to reduce to this case by performing toric blow-ups.

Dynamic wetting phenomena are present in many everyday situations where liquids interact with surfaces. Understanding and controlling the dynamics of droplets wetting solid surfaces is important in various applications such as boiling and condensation heat transfer, printing and coating, and microfluidic processes. However, modeling their dynamics is not easy because they are multiscale systems in which the advancing or receding of a nanoscale-thick contact line is linked to the behavior of the entire millimeter-scale droplet. In the Thermal Energy Engineering lab (TEEL) at the University of Tokyo, together with the collaborators, we have been investigating the rapid spreading of droplets on solid surfaces as a model system, where the non-equilibrium nature of energy dissipation at the contact line becomes evident. On a partially wetting solid surface, when capillary forces drive droplet spreading, the advancement of the contact line is governed by viscous forces, inertial forces, or contact-line friction. Through experiments, we demonstrated that the dominant physical mechanisms can be switched by tuning droplet properties, surface microstructure [1], or applied electric field [2]. We modeled and reproduced these experiments using a phenomenological parameter that quantifies the contact-line friction coefficient and mapped a phase diagram of dominant physical factors in a dimensionless parameter space. With the knowledge, we realized anisotropic wetting and droplet transport by taking advantage of the fact that the dynamic behavior of droplets can be controlled through solid surfaces when contact line friction is dominant [3,4]. Furthermore, in our recent experiments on droplet oscillation [5] and droplet sliding [6] on solid surfaces functionalized with various self-assembled monolayers (SAMs), we observed that nanoscale surface chemistry and morphology significantly influence contact-line dynamics. This suggests that contact-line friction originates from nanoscale energy dissipation, though the dissipation mechanism remains unclear, and thus, it calls for collaboration with experts with multiscale discipline.

C*-seminar by Ali Miller (Southern University of Denmark).

There are several approaches to studying configuration spaces of points on curves. Examples are the Deligne-Mumford and Hassett spaces or, in the case of points on a projective line, a straightforward GIT construction. Deligne and Mostow further investigated the situation where moduli spaces of weighted points on the projective line have ball quotient models. This leads to a finite set of configuration spaces of ordered or partially ordered points on P^1. In all of these cases, the GIT compactification and the Baily-Borel compactification of the ball quotient are isomorphic. These spaces have natural (partial) desingularizations, namely the Kirwan blow-up and the toroidal compactification. It follows from results of Gallardo-Kerr-Schaffler and Kiem-Moon that, in the case of ordered configurations, the Deligne-Mostow map lifts to an  isomorphism of these compactifications. This can fail for only partially ordered configurations. The main result of this talk is to explain a criterion exactly when these two compactifications coincide. This is also related to the Log Minimal Model Program. This is joint work with Yota Maeda.   

C*-algebra seminar by John Quigg (Arizona State University)

Emmett B. Kendall is a fifth year PhD candidate in the Department of Statistics at North Carolina State University (NC State). He graduated from the University of Florida (UF) with a B.S. in Mathematics and a Minor in Statistics. 

His research interests include hidden Markov models, Bayesian inference, biomedical statistics, functional data analysis, multi-task learning and regression discontinuity designs. 

QOMBINE seminar by Joel Rajakumar (University of Maryland)

Paolo Giordani is a professor of Financial Econometrics at the Norwegian Business School in Oslo.

His main research interests are statistical machine learning, Bayesian inference, and volatility

QOMBINE seminar by Randy Lin (University of Amsterdam)

Uneven solid surfaces are ubiquitous in Nature and can significantly impact fluid flow over them. In this presentation I will discuss two different configurations were the wall unevenness govern fluid transport.
First, I will consider wet ceilings. When liquid is coated on an upside-down surface, it destabilizes to form pendant drops surrounded by a thin film of liquid. I will show that these pendant drops ‘feel’ surface defects even though they have no contact line. The defects induce a gravito-capillary pinning-like force that can be harnessed to control the drop motion.
Second, I will consider hairy pipes. Many biological surfaces are covered with long and elastic filaments or ‘hairs’. I will show that when a fluidic channel is covered with hairs, the hydraulic resistance can become non-linear. This non-linearity is mediated by the hair flexibility and degree of channel obstruction and can be rationalized with a multi-scale model.

Arnt-Børre Salberg is a Chief Research Scientist at the Norsk Regnesentral, affiliated with the Department of BAMJO (Image Analysis, Machine Learning and Earth Observation).  

His research primarily focuses on the developing deep learning, computer vision, and remote sensing methods to image data. This includes work on forest mapping and monitoring, marine science applications, coastal habitat mapping, foundation models, and analysis of data from various sensors like satellites, seismic, and marine echosounders.

I will explain how to use the motivic volume formula and toric degenerations to study the rationality problem for complete intersections in Grassmannians, in particular Gr(2,5).

Hélène Ruffieux is a Senior Research Fellow at the MRC Biostatistics Unit, University of Cambridge. She holds a PhD in Mathematics from EPFL, Switzerland. Her research interests broadly lie in the development of Bayesian methods and their application to open problems in biomedicine, with a focus on scalable hierarchical modelling approaches for variable selection, latent structure discovery and network estimation, in high-dimensional or temporal data settings.