Speaker: Emmanuele Battista, Postdoc
Abstract: In this seminar, we investigate a Schwarzschild metric whose signature changes upon crossing the event horizon. In particular, when r > 2M the metric has the usual Lorentzian signature; then, at r = 2M it becomes degenerate, and when r < 2M it attains the ultrahyperbolic signature. In this scenario, the time variable is real-valued outside the event horizon and becomes imaginary inside it. This geometry gives rise to what we term a Lorentzian-Euclidean black hole. The underlying Riemann tensor exhibits Dirac-delta-like singularities which we regularize by employing the Hadamard partie finie technique. In this way, we demonstrate that the Lorentzian-Euclidean metric represents a solution of the vacuum Einstein equations. The analysis of the motion of radially moving observers reveals that the black-hole singularity can be avoided. The seminar is based on ArXiv: 2404.17267.
Location: The DIAS Meetingroom Syd (V22-503a-2)
You can also join via Zoom (passcode: 060379).
The event is open to all.
Abstract: In this seminar, we investigate a Schwarzschild metric whose signature changes upon crossing the event horizon. In particular, when r > 2M the metric has the usual Lorentzian signature; then, at r = 2M it becomes degenerate, and when r < 2M it attains the ultrahyperbolic signature. In this scenario, the time variable is real-valued outside the event horizon and becomes imaginary inside it. This geometry gives rise to what we term a Lorentzian-Euclidean black hole. The underlying Riemann tensor exhibits Dirac-delta-like singularities which we regularize by employing the Hadamard partie finie technique. In this way, we demonstrate that the Lorentzian-Euclidean metric represents a solution of the vacuum Einstein equations. The analysis of the motion of radially moving observers reveals that the black-hole singularity can be avoided. The seminar is based on ArXiv: 2404.17267.
Location: The DIAS Meetingroom Syd (V22-503a-2)
You can also join via Zoom (passcode: 060379).
The event is open to all.
- Organizer: Quantum Field Theory Center
- Address: Fioniavej 34, 5230 Odense M
- Contact Email: damiapaciarinim@qtc.sdu.dk
- Download slides from the talk: https://www.sdu.dk/-/media/files/forskning/quantum-field-theory-centre/friday-journal-club/170524-Battista.pdf
- Add to your calendar: https://eom.sdu.dk:443/events/ical/1e72f633-51f6-4425-af66-b524031d468a