Exact solutions to Einstein’s field equation coupled to dust

Quando:
Novembre 4, 2021@11:00 am–12:00 pm
2021-11-04T11:00:00+00:00
2021-11-04T12:00:00+00:00
Dove:
Aula 603 e online
Aula 603 e online

Seminario di Fisica Teorica INFN/DIFI – Davide Astesiano (Università dell’Insubria)

To analyze the dynamics of a single spiral galaxy, we will discuss the known class of exact stationary axially-symmetric solutions to Einstein gravity coupled with neutral dust. Differently from the Newtonian description of the same system where all the quantities are completely fixed once the velocity or the matter distribution are known, the class of the relativistic solutions provides additional degrees of freedom, making the applications of this system much more interesting and wide. Up to now, from the relativistic perspective the already proposed models for galaxies are the co-rotating and the differentially rotating model. While in the first case the velocity of the dust satisfies L_u(g) = 0, in the second case it differs from zero. What is interesting about these solutions is that the low energy limits are non equivalent to the Newtonian theory. In particular, the differentially rotating case generalize the known results of Balasin and Grumiller and further highlights the discrepancy between Newtonian theory of gravity and general relativity at low velocities and energy densities. Using these exact solutions, we push forward the idea that the inertia of the gravitational field can simulate dark matter effects. In fact, we show that non co-rotance further reduces the amount of energy density required to explain the rotation curves for spiral galaxies.

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Per partecipare in presenza, prenotarsi seguendo il link
https://docs.google.com/document/d/1uaw5DHG0VykTHraDiAqYjbLFXsrOIXaftj_n04sj4PE/edit?usp=sharing
oppure per partecipare su Zoom, collegarsi al meeting
Topic: Theory and Pheno seminars
https://infn-it.zoom.us/j/8573185271
Meeting ID: 857 318 5271
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