Talks

This class is an introduction to the 2-species competitive Lotka-Volterra model. We will cover three canonical outcomes--coexistence, dominance and bistability-- for the pairwise competition between species. We will also use the model to predict co-culture's responses to different perturbations, and see how these predictions were experimentally verified in microcosms.

In these lectures, I discuss how GWs are produced by cosmological phase transitions. We start by a short recap of gravitational waves and then move to early attempts using pairs of bubbles and the envelope approximation. Next we cover the energy budget of phase transitions and the impact of sound waves. Finally I comment on recent developments.
 

Area metrics define generalized geometric backgrounds to describe spacetime. They are suggested at various places in classical field theory and arise within different approaches to quantum gravity. On these grounds, after introducing the notion of an area metric, I will consider covariant area-metric actions to second order in fluctuations and derivatives. I will then show how these give rise to effective length-metric actions with a distinct nonlocal Weyl-curvature squared term beyond general relativity. Finally, I will point out possible implications and routes for phenomenology.