Talks

For a theory whose half-BPS sector can be described by N=4 quiver quantum mechanics, its BPS algebra (à la Harvey-Moore) is given by the quiver Yangian. I will first review the construction of the BPS quiver Yangians and then discuss their applications, such as on BPS counting, Gauge/Bethe correspondence, and knot-quiver correspondence. 

Zoom Link: TBD

I will argue that a fruitful strategy to make progress in quantum gravity is to connect distinct approaches and transfer methods and ideas from one approach to another. As a concrete example, I will explain recent results in causal-set quantum gravity. The first, namely the construction of a higher-order curvature operator in causal sets, is motivated by the idea to use causal sets as a Lorentzian regularization of the gravitational path integral, in which one can search for asymptotic safety. The second, namely an upper bound on the mass of scalars is inspired by the "matter matters" program in asymptotically safe quantum gravity, in which observational tests of quantum gravity are based on gravity's interplay with matter. I will argue that a similar program for causal sets can provide new, observationally motivated constraints on causal set quantum gravity.To provide background and motivation for these results, I'll provide brief and pedagogical introductions into the key features and key open challenges of both asymptotically safe quantum gravity as well as causal set quantum gravity.

Zoom Link: https://pitp.zoom.us/j/99855484685?pwd=M0IvOFk1OWNCdVlZVDdkUFQ4MzZKUT09

In this talk, I will start by motivating the introduction of new- (quantum) physics effects in black hole spacetimes through a principled-parameterized approach. I will then discuss how these new-physics effect can affect the formation of non-singular black holes by applying the principled-parameterized approach to gravitational collapse. This will serve as a motivation to study non-singular black hole parameterizations beyond circularity. Finally, I will present how quantum gravity effects linked to these guiding principles can be traced back to observational imprints in synthetic (ng)EHT images, in particular in photon rings.

Zoom Link: https://pitp.zoom.us/j/93325159463?pwd=aGlQUHJzWWg1d3hBRzAwOURGY3NFdz09

There are fascinating new insights we could achieve if we succeeded in connecting quantum gravity to particle physics in the visible and the dark universe. However, making such a connection is challenging, because the typical scale of quantum gravity is believed to be far from the typical scales in particle physics. I will exploit lever arms that could make it possible to bridge this gap in scales.  To provide concrete examples for these ideas, I will review recent results on the proton lifetime in quantum gravity, the effects of asymptotically safe quantum gravity on properties of Standard Model matter and the effects of asymptotically safe quantum gravity on simple models of dark energy and dark matter.

Zoom Link: https://pitp.zoom.us/j/96545839038?pwd=UG1IVzJPWUZGa2ovOFhzdHBhOFhOdz09

In this talk, I will present three algorithms that address distinct variants of the problem of testing quantum states. First, I will discuss the problem of statistically testing whether an unknown quantum state is a matrix product state of certain bond dimension or it is far from all such states. Next, I will demonstrate a method for testing whether a bipartite quantum state, shared between two parties, corresponds to the ground state of a given gapped local Hamiltonian. Finally, I will present a scheme for verifying that a machine learning model of an unknown quantum state has high overlap with the actual state.

Zoom Link: https://pitp.zoom.us/j/99250127489?pwd=UCtXUi9zMzJZamppT29DbWtJcWU3Zz09

Epidemiological models, like meteorological models, have their origins in simple equations that nevertheless managed to capture the essence of the phenomena studied. Two physicians, Ronald Ross and Anderson G. McKendrick (both closely related to India), and a chemist, William O. Kermack, laid the foundations of epidemiological modeling around the same time that physicist Lewis Fry Richardson proposed the first weather prediction models. Despite their success in explaining the phenomenology observed in contagion processes, the practical application of epidemiological models was not comparable to those dedicated to meteorology, at least in terms of their predictive nature. The arrival of the 21st century brought with it the democratization of the Internet which, together with advances in the capture of data on human activity, made it possible to describe the skeleton of interactions through which infectious diseases are transmitted. In this colloquium we will describe the efforts invested during the last two decades to incorporate into epidemic models ingredients such as the complexity of contact networks, patterns of human mobility at different geographical scales and the different temporal scales associated with human interactions. With this information available, the theoretical and computational tools of complex systems and network science have demonstrated their usefulness in analyzing real epidemiological problems, developing theoretical and computational frameworks that allow not only to accurately reproduce the spatiotemporal trajectory of an epidemic, but also to evaluate epidemiological control strategies.