**Contact Info**

Department of Applied Mathematics

University of Waterloo

Waterloo, Ontario

Canada N2L 3G1

Phone: 519-888-4567, ext. 32700

Fax: 519-746-4319

PDF files require Adobe Acrobat Reader

Friday, January 21, 2022 10:30 AM EST

Zoom (please email amgrad@uwaterloo.ca or the student for the meeting link)

Jose Polo Gomez | Applied Mathematics, University of Waterloo

AQFT meets RQI: from foundations of quantum field theory to thermodynamics and machine learning

The fields of relativistic quantum information (RQI) and algebraic quantum field theory (AQFT) have proven to be successful in improving our understanding of several problems in quantum field theory, especially in curved backgrounds. In this talk, we will discuss a few lines of work in which combining the approaches and techniques of RQI and AQFT turns out to be fruitful.

First, we will consider the problem of measuring quantum fields. Representing measurements in quantum field theory in a way consistent with the fundamental framework of the theory (e.g., respecting relativity) has been a long-standing open foundational problem since Rafael Sorkin pointed it out in 1993. After reviewing previous approaches, we will show that a consistent measurement theory with arguably all the desirable properties can be built using particle detectors. To build this measurement scheme, we used an approach based on keeping track of where the information of the measurement is accessible, and we formalized this approach using the algebraic formalism. We will briefly discuss the prospective applications of this measurement framework, including the possibility of applying it to model measurements with so-called macrodetectors, based on work in preparation.

Second, we will consider the extension of thermodynamics to quantum field theory. We will review some of the conceptual difficulties of quantum thermodynamics, as well as the first works on its field-theoretical extension.

Finally, we will talk about studying the spacetime structure using quantum fields. It is well known that local correlations present in some distinguished states of quantum fields (such as the vacuum) contain information about the global structure of spacetime (its topology and geometry), and that this information can be harvested locally by particle detectors. This would allow targeting specific global parameters to be estimated by local measurements, and the use of machine learning techniques to optimize the information gathering protocol may allow us to take this idea to realistic setups.

**Contact Info**

Department of Applied Mathematics

University of Waterloo

Waterloo, Ontario

Canada N2L 3G1

Phone: 519-888-4567, ext. 32700

Fax: 519-746-4319

PDF files require Adobe Acrobat Reader

University of Waterloo

University of Waterloo

43.471468

-80.544205

200 University Avenue West

Waterloo,
ON,
Canada
N2L 3G1

The University of Waterloo acknowledges that much of our work takes place on the traditional territory of the Neutral, Anishinaabeg and Haudenosaunee peoples. Our main campus is situated on the Haldimand Tract, the land granted to the Six Nations that includes six miles on each side of the Grand River. Our active work toward reconciliation takes place across our campuses through research, learning, teaching, and community building, and is co-ordinated within our Office of Indigenous Relations.