[Astro] [CAPT] Particle Cosmology and Gravity Seminar this week: Kieran Wood (Nottingham)

[Swagat Mishra]

Dear All,

                  We have a seminar this week whose details are provided below.

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Speaker: Kieran Wood (Nottingham)

Seminar date: April 15th , Tuesday, 1 pm UK time

Venue: Seminar Room A 113 (Cripps North Building, CAPT)


Title: How to build a dimension


Abstract:  In this talk, I will aim to shed new light on an old question, namely: “what does gravitational physics in an additional compact dimension look like to a lower dimensional observer?” Kaluza-Klein tells us that we should expect to see (infinite) towers of massive spin-2 fields; more recently, theories involving exactly these kinds of fields - so-called multi-gravity theories - have undergone a resurgence, thanks to many interesting theoretical and phenomenological developments. These ideas are related: multi-gravity can be thought of as arising from higher dimensional GR upon discretising the extra dimension, although the strict correspondence between the two theories only holds when one does this *after* gauge fixing the higher dimensional lapse function. The lapse provides crucial structure to higher dimensional GR: it ensures full diffeomorphism invariance and enforces the Hamiltonian constraint. Thus, upon deconstruction, important information related to the extra dimension is missing in the resulting multi-gravity theory; consequently, one could never hope to recover GR in its entirety upon taking the appropriate continuum limit. Here, I develop an improved deconstruction procedure that maintains the free lapse, and show that the correct deconstructed theory should actually be multi-gravity equipped with additional dynamical scalar fields, whose field equations encode the higher dimensional Hamiltonian constraint. I use the example of Randall-Sundrum brane cosmology to demonstrate this correspondence explicitly. This opens up a number of interesting avenues for studies of new, viable theories of modified gravity, and potentially a means to probe higher dimensional physics through a lower dimensional lens.

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Link to join:

 https://teams.microsoft.com/l/meetup-join/19%3ameeting_OGM3OTk5NzQtZWEwZS00ZmUyLTk3MGUtZjFhY2M5OTU2MjI1%40thread.v2/0?context=%7b%22Tid%22%3a%2267bda7ee-fd80-41ef-ac91-358418290a1e%22%2c%22Oid%22%3a%22f3250584-4b5f-48fa-a897-08e77f2246b7%22%7d



List of upcoming Seminars:

15th April: Kieran Wood (Nottingham)
22nd April: TBD
29th April: Daniel Panizo (Kyoto U)
6th May: Ameek Malhotra (Swansea)
13th May: David Trestini (Southampton)
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With Regards,
-Elisa & Swagat




Swagat Saurav Mishra,

Postdoctoral Research Associate

​

Particle Cosmology Group,

Centre for Astronomy and Particle Theory,

University of Nottingham, Nottingham NG7 2RD, UK.

Website: https://swagatam18.wordpress.com/

Research Link:https://inspirehep.net/authors/1517353

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