Wednesday May 11th 2016 at Geneva – Francesca Vidotto (Radboud University Nijmegen): How classical spacetime emerges in Loop Quantum Gravity

Abstract: “Is space an entity or a net of relations? Is classical spacetime emergent? If it is emergent, what is it emerging from? Is spacetime fundamentally discrete or continuous? Is time an ingredient of the fundamental equations of the world? Is time flowing? These philosophical questions need to find an answer in a concrete realisation of a quantum theory of gravity. I illustrate the basics of Loop Quantum Gravity and the specific answers that each of these (philosophical) questions finds in the context of this (physical) theory. I focus on the notion of spacetime emergence: I argue that classical spacetime emerges from the quanta of spacetime, no differently from the emergence of electromagnetism having photons. This quantum emergence is studied in Loop Quantum Gravity, where there is a notion of classical limit. This limit should not be confused with a thermodynamical limit, that may exist but it is not necessary to recover classical spacetime. These ideas can be illustrated in analogy with the case of electromagnetism.” In terms of technical difficulty, this talk rates 4/5 

We have been catching up a bit, posting lectures – now on YouTube you can see:

Eddy Keming Chen

Alastair Wilson

Jonathan Dorsey

 James Read

Karen Crowther

Abstracts, links for these (and more) in the speakers pages, accessed above.

Here are the talks in the next few weeks:

• Wednesday May 11th 2016 at Geneva – Francesca Vidotto (Nijmegen): TBA

• Wednesday May 25th 2016 at UIC – Henrique Gomes (Perimeter Institute): TBA

• Friday June 17th 2016 at UIC – DOUBLE HEADER!

Radin Dardashti (Munich Center for Mathematical Philosophy, and Geneva): TBA

Juliusz Doboszewski (Jagiellonian University, and Geneva): TBA

More information on the Speakers page above.

We are very happy to announce that Djordje Minic (Virginia Tech) has joined the faculty of the summer institute – fewer than two months to go!

• Wednesday April 27th 2016 at UIC – Karen Crowther: The Correspondence Principle in Quantum Gravity

Abstract: “The difficulties in discovering a theory of quantum gravity are due not only to its apparently extreme experimental inaccessibility, but the fact that there are no commonly accepted, formally established constraints that define its basic structure and objectives. I critically examine the role of the correspondence principle in quantum gravity, to evaluate its prospects as such a constraint. I find that there is a form of correspondence that serves as an essential heuristic guide in developing the theory, but that another form of correspondence has acquired a status of undue weight. It seems that the stress on deriving general relativity in the low-energy regime is unwise at this stage of theory-development, and possibly altogether.”  In terms of technical difficulty, this talk rates 3/5  

We plan to live stream all of the talks this week on our YouTube channel (https://www.youtube.com/channel/UC_VhTJBl6Mpmfjj5q832rjg) — as we think we have solved the tech problems. In the menu of options, select ‘live streams’ at around 16:15 Swiss time tomorrow, and you should see it.

Two short talks, from both sides of the Atlantic:

(1) In Geneva, Giuliano Torrengo (Milan): The experience of the passage of time

(2) In Chicago, James Read (Oxford): Background Independence and Holography

For more information follow the links above.

Our speaker this week is Oliver Pooley, giving a talk in Geneva on Relativity and the growing block. Join us there, or at UIC via video link. More details in the links above.

We are thrilled to announce the winners of our first essay prize!

In alphabetical order:
“Back to Parmenides” Henrique Gomes (Perimeter Institute)
“Taking Up Superspace” Tushar Menon (Oxford)
“What can (mathematical) categories tell us about space time?” Ko Sanders (Leipzig)

We have the polished version of Richard Dawid’s talk on YouTube now — and the livestream version of Dean Rickles’ is also available (we are busy polishing a version of that too!).