Einstein’s Magnum Opus, The field equations of general relativity
This article is written as a celebration of the 110th anniversary of the first appearance of one of the most elegant theories that describe our Universe: Einstein’s General Theory of Relativity. After publishing his special theory of relativity (dealing with systems of reference moving with constant velocities), along with other monumental theories in 1905, Einstein would roll up his sleeves to attempt (and succeed) to formulate a more general theory that would include gravitation (and thus, accelerating systems). For that, he had to work with his close friend, the mathematician Marcel Grossmann, who was competent in the mathematics Einstein needed to form his extended theory, differential geometry. On November 25, 1915, Einstein publicly announced that he had...
Read MoreDelayed outflows in AT2018hyz.
As it is known, tidal forces are gravitational effects caused by a gravitational gradient applied to a body. Meaning, a force of different amplitude is being applied to different parts of a body, resulting in a tendency to change its shape. Now, if a cosmic object passes close enough to a supermassive black hole (SMBH), that the tidal force can overcome the self-gravity of the object, it leads to a tidal disruption event (TDE). Such an event was observed during October, 2018, when a SMBH devoured a star, forming a transition accretion disk. It was named AT2018hyz. AS TDEs are quite common and at that time it didn’t seem to be anything particularly special for AT2018hyz, researchers moved on, trying to use the precious telescope type, better. However, about three...
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