High Energy Physics Seminar next Tuesday - Poddar

[HECAP - Margherita Di Giovannantonio]

*_HIGH ENERGY PHYSICS SEMINARS_**__*


*Tuesday, 21 October *2025, at *16:00* - *L. Stasi Seminar 
Room***-*https://indico.ictp.it/event/11200/*


Tanmay Kumar Poddar (INFN Salerno)



*“Constraints on Ultralight Scalars from Compact Stars: Pulsar Spin-Down 
and Black Hole Superradiance"*
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*

_Abstract_

Ultralight scalar fields coupled to photons or neutrinos can leave 
distinctive imprints on astrophysical observables, particularly through 
measurements of pulsar spin-down luminosities and black hole 
superradiance. If such scalars are sourced by the electromagnetic fields 
of neutron stars, they can develop extended long-range profiles, unlike 
axions, leading to observable effects on the redshift and pulsar 
spin-down rates.

In this talk, I will discuss the interaction between scalar fields and 
the electromagnetic environment of highly magnetised stars and explore 
the resulting phenomenological consequences. I will also examine how 
scalar fields participating in black hole superradiance can be 
constrained when their interaction with the cosmic neutrino background 
suppresses the instability. By comparing theoretical predictions with 
observed black hole spin distributions, we can place strong bounds on 
the scalar-neutrino coupling, independent of whether these scalars 
constitute dark matter.


To attend via _*Zoom*_, please *_register_* here:
https://zoom.us/meeting/register/fRu0KGneR7yR1ykQVPYu5w