## 2022-2023

Upcoming talks

3 June 2023

**Helen Meskhidze (UCI), “Torsion in the Classical Spacetime Context**“

Teleparallel gravity, an empirically equivalent counterpart to General Relativity, represents the influence of gravity using torsional forces. It raises questions about theory interpretation and underdetermination. To better understand the torsional forces of Teleparallel gravity, we consider a context in which forces are better understood: classical spacetimes. We propose a method of incorporating torsion into the classical spacetime context that yields a classical theory of gravity with a closed temporal metric and spacetime torsion. We then prove a result analogous to the Trautman degeometrization theorem, that every model of Newton-Cartan theory gives rise, non-uniquely, to a model of this theory.

Helen’s paper is available here.

Past talks

6 May 2023** **

**Eugene Chua (UCSD), “T Falls Apart: On the Status of Classical Temperature in Relativity”**

Abstract: I argue that the classical temperature concept falls apart in special relativity by examining four consilient procedures for establishing classical temperature: Carnot processes, thermometers, kinetic theory, and black-body radiation. I show that their relativistic counterparts demonstrate no such consilience. I suggest two interpretations for this situation: eliminativism akin to simultaneity, or pluralism akin to rotation.

March 18 2023

**Event: Math-First Structural Realism Workshop. **

11 February 2023

**Laura Ruetsche (Michigan), “Unborn Again: Probability in Bohmian Mechanics”**

Why are quantum probabilities encoded in measures corresponding to wave functions, rather than by a more general class of measures? Call this question *Why Born?*. Orthodox quantum mechanics has a compelling answer to *Why Born?*, I argue, but Bohmian mechanics might not. I trace Bohmian difficulties with *Why Born?* to its *antistructuralism*, its denial of physical significance to the algebraic structure of quantum observables, and propose other cases where Bohmian antistructuralism might have an explanatory cost.

If you would like to read more in advance, there are short and long versions of the manuscript available.

14 January 2023

**Alex Franklin (Kings College London), “Incoherent? No, Just Decoherent: How Quantum Many Worlds Emerge**“

The modern Everett interpretation of quantum mechanics describes an emergent multiverse. The goal of this talk is to offer a perspicuous characterisation of how the multiverse emerges making use of a recent account of (weak) ontological emergence. This will be cashed out with a case study that identifies decoherence as the mechanism for emergence. The greater metaphysical clarity enables the rebuttal of a critique by Dawid and Thébault (2015) that casts the emergent multiverse ontology as incoherent; responses are also offered to challenges to the Everettian approach from Maudlin (2010) and Monton (2013).

3 December 2022:

**Ricardo Karam (Copenhagen), “Historical episodes of the complexification of physics“**

Complex numbers were invented (or discovered?) byItalian mathematicians in the 16th century as pragmatic tools to solve cubicequations, and not much attention was given to questions related to their “existence”.However, this changed significantly in the end of the 18th century, whencomplex numbers were given a geometrical interpretation. Such concretizationmotivated physicists to use these numbers to model all kinds of phenomena, aprocess that has been called “complexification of physics” by Salomon Bochner.The talk will present different historical episodes of the complexification, highlighting, in each case, how and why complex numbers became useful to physicists.

29 October 2022:

**Jingyi Wu (UC Irvine), “Explaining Universality: Infinite Limit Systems in the Renormalization Group Method”**

I analyze the role of infinite idealizations used in the renormalization group (RG hereafter) method in explaining universality across microscopically different physical systems in critical phenomena. I argue that despite the reference to infinite limit systems such as systems with infinite correlation lengths during the RG process, the key to explaining universality in critical phenomena need not involve infinite limit systems. I develop my argument by introducing what I regard as the explanatorily relevant property in RG explanations: the linearization* property; I then motivate and prove a proposition about the linearization property in support of my view. As a result, infinite limit systems in RG explanations are dispensable.

If you would like to read Jingyi’s paper in advance, it is available here.