[Astro] [CAPT] Extra seminar today: Javier Carballo

[Laura Sberna (staff)]

Correction: the seminar will be in Pope B23. Sorry about the confusion! 

> On 10 Dec 2025, at 10:43, Laura Sberna (staff) <Laura.Sberna at nottingham.ac.uk> wrote:
> 
> A reminder: in 30 minutes in C05 Physics.
> 
>> On 5 Dec 2025, at 12:05, Laura Sberna (staff) <Laura.Sberna at nottingham.ac.uk> wrote:
>> 
>> Dear all,
>> 
>> We will have an extra seminar next week. The speaker, Javier Carballo, together with Paolo Arnaudo, will be visiting us from 9 December to 11 December from the University of Southampton. Please get in touch with them (cc'd) if you would like to arrange a meeting.
>> 
>> When: 11am, Wednesday December 10th
>> Where: C05 Physics
>> 
>> Javier Carballo (U of Southampton)
>> 
>> "A complete mode decomposition of black hole perturbations"
>> 
>> It is well known that quasinormal modes (QNMs) do not form a complete basis for linear black hole perturbations. In particular, retarded Green's functions of black holes can only be decomposed as a convergent sum of QNMs at sufficiently late times. In this talk, I will show that Green's functions can be expanded as a convergent mode sum everywhere in spacetime. When QNMs fail at early times, a sum of Matusbara modes (MMs) associated to the horizon temperature converges instead. I will present the case of the Schwarzschild black hole, where the branch cut is resolved into a set of de Sitter modes by adding a small positive cosmological constant. Based on 2510.18956.
>> 
>> Best,
>> Laura
> 
> _______________________________________________
> NCOG-people mailing list
> NCOG-people at lists.nottingham.ac.uk
> https://lists.nottingham.ac.uk/mailman/listinfo/ncog-people
_______________________________________________
CAPT mailing list
CAPT at lists.nottingham.ac.uk
https://lists.nottingham.ac.uk/mailman/listinfo/capt