Talks

Readings:
Black Holes in Classical General Relativity and Beyond, by D. Psaltis https://www.worldscientific.com/doi/10.1142/9789811282676_0001
The Kerr spacetime: A brief introduction, by M. Visser https://arxiv.org/pdf/0706.0622

The talk will discuss a different modification to the Bala-Goyal framework.  Here agents form beliefs based on their own experience and that of their neighbors, just like in the base model.  But they do not always perform the action they believe is best.  Instead, they weigh their expected payoff from taking a given action against their preference for conforming with their neighbors.  This modification leads to several new effects, including a different way in which polarization may arise, this time due to network structure.  We will conclude by reflecting on what it means that there are multiple, apparently distinct ways in which polarization can arise in simple models. 

Philosophers and economists have used cultural evolutionary models of bargaining to understand issues related to fairness and justice, and especially how fair and unfair conventions and norms might arise in human societies. One line of this research shows how the presence of social categories in such models allows for inequitable equilibria that are not possible in models without social categories. This is taken to help explain why in human groups with social categories inequity is often the rule rather than the exception. But in previous models, it is typically assumed that these categories are rigid, easily observable, and binary. In reality, social categories are not always so tidy. We introduce evolutionary models where the tags connected with social categories can be flexible, variable, or difficult to observe, i.e., where these tags can carry different amounts of information about group membership. We show how alterations to these tags can undermine the stability of unfair conventions. We argue that these results can inform projects intended to ameliorate inequity, especially projects that seek to alter the properties of category markers.

In this talk, I will present a sewing-factorization theorem for conformal blocks in arbitrary genus associated to a (possibly nonrational) $C_2$-cofinite VOA $V$. This result gives a higher genus analog of Huang-Lepowsky-Zhang's tensor product theory. Moreover, I will explain the relation between our result and pseudotraces, and confirm some of the conjectures by Gainuditnov-Runkel. The relationship between our result and coends will also be discussed. The talk is based on an ongoing project (arXiv: 2305.10180, 2411.07707) joint with Bin Gui.