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CATEGORIES:Wednesday HEP-GR Colloquium
SUMMARY:Testing the gravitational sector with black hole p
erturbations - Riccardo Penco\, Carnegie Mellon Un
iversity
DTSTART;TZID=Europe/London:20201104T141500
DTEND;TZID=Europe/London:20201104T151500
UID:TALK153049AThttp://talks.cam.ac.uk
URL:http://talks.cam.ac.uk/talk/index/153049
DESCRIPTION:Gravitational wave observations allow us to probe
directly the nature of black holes. This provides
us with an unprecedented opportunity to test the g
ravitational sector. I will argue that effective f
ield theory (EFT) techniques provide a natural fra
mework to constrain possible departures from Gener
al Relativity (GR) in a model independent way.\n\n
To illustrate this point\, in this talk I will foc
us on a particularly striking departure from the b
lack hole solutions of GR\, namely the existence o
f scalar hair (i.e. one or more scalar fields with
a non-trivial radial profile). I will introduce a
n EFT for perturbations around spherically symmetr
ic spacetimes with a scalar hair\, and then discus
s a couple of applications in different regimes.\n
\nFirst\, I will apply this formalism to study qua
si-normal modes (QNM) of static black holes with a
scalar hair. Assuming that the deviation of the b
ackground from Schwarzschild is small\, I will use
a WKB approximation to introduce the notion of "l
ight ring expansion" -- an approximation analogous
to the slow-roll expansion used for inflation --
and provide a model independent parametrization of
the QNM spectrum. Second\, if time allows it\, I
will use this EFT to calculate the power emitted b
y an extreme mass-ratio binary inspiral in the pos
t-Newtonian limit.
LOCATION:ONLINE - Details to be sent by email
CONTACT:Scott Melville
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