2 research outputs found
Fundamental scaling relationships revealed in the optical light curves of tidal disruption events
We present fundamental scaling relationships between properties of the
optical/UV light curves of tidal disruption events (TDEs) and the mass of the
black hole that disrupted the star. We have uncovered these relations from the
late-time emission of TDEs. Using a sample of 63 optically-selected TDEs, the
latest catalog to date, we observed flattening of the early-time emission into
a near-constant late-time plateau for at least two-thirds of our sources.
Compared to other properties of the TDE lightcurves (e.g., peak luminosity or
decay rate) the plateau luminosity shows the tightest correlation with the
total mass of host galaxy (-value of , with a residual
scatter of 0.3 dex). Physically this plateau stems from the presence of an
accretion flow. We demonstrate theoretically and numerically that the amplitude
of this plateau emission is strongly correlated with black hole mass. By
simulating a large population of TDEs, we determine a plateau luminosity-black
hole mass scaling relationship well described by . The observed plateau
luminosities of TDEs and black hole masses in our large sample are in excellent
agreement with this simulation. Using the black hole mass predicted from the
observed TDE plateau luminosity, we reproduce the well-known scaling relations
between black hole mass and galaxy velocity dispersion. The large black hole
masses of 10 of the TDEs in our sample allow us to provide constraints on their
black hole spins, favouring rapidly rotating black holes. We add 49 (34) black
hole masses to the galaxy mass (velocity dispersion) scaling relationships,
updating and extending these correlations into the low black hole mass regime.Comment: 24 pages + appendices, 20 figures. Submitted to MNRAS, comments
welcom
Lectures on Generalized Symmetries
These are a set of lecture notes on generalized global symmetries in quantum
field theory. The focus is on invertible symmetries with a few comments
regarding non-invertible symmetries. The main topics covered are the basics of
higher-form symmetries and their properties including 't Hooft anomalies,
gauging and spontaneous symmetry breaking. We also introduce the useful notion
of symmetry topological field theories (SymTFTs). Furthermore, an introduction
to higher-group symmetries describing mixings of higher-form symmetries is
provided. Some advanced topics covered include the encoding of higher-form
symmetries in holography and geometric engineering constructions in string
theory. Throughout the text, all concepts are consistently illustrated using
gauge theories as examples.Comment: 138 pages, added reference