Talk detail

Participant	Bianchi, Eugenio
Institution	Penn State University - Department of Physics, 104 Davey Lab, PMB #262 - University Park - PA - USA

Session	QG1	Accepted		Order	Time
Talk	Oral abstract	Title	Gluing polyhedra with entanglement in loop quantum gravity
Coauthors
Abstract	In a spin-network basis state, nodes of the graph describe un-entangled quantum regions of space, quantum polyhedra. In this talk, I discuss how entanglement between intertwiner degrees of freedom enforces gluing conditions for neighboring quantum polyhedra. In particular, I introduce Bell-network states, entangled states defined via squeezed vacuum techniques. I present an analysis of correlations of quantum polyhedra in a dipole, a pentagram, and a generic graph. Finally, I show that vector geometries, structures with neighboring polyhedra having adjacent faces glued back-to-back, arise from Bell-network states. The results presented show clearly the role that entanglement plays in the gluing of neighboring quantum regions of space.
Pdf file

Session	QG2	Accepted		Order	Time
Talk	Oral abstract	Title	Bekenstein-Hawking entropy and the spin of primordial black holes
Coauthors
Abstract	I discuss the phenomenological implications of a prediction shared by all current approaches to quantum gravity: the Bekenstein-Hawking entropy formula. I show that this formula defines a microcanonical ensemble for the spin of black holes. In this ensemble, most of the configurations have small spin as higher spins correspond to a smaller entropy. The ensemble describes primordial black holes formed in the early universe where no orbital mechanism selects a specific spin. The prediction is that primordial black holes have spins peaked at 0, and first-generation primordial mergers have spin peaked at 0.69. I present a preliminary statistical analysis of this prediction, together with a comparison to current astrophysical models of spin alignment, for the best-measured spin parameters through GWs of all the six binary black hole mergers discovered by aLIGO and AdV detectors so far. The imminent transition from single gravitational-wave events to population analyses could provide the first experimental test of the Bekenstein-Hawking entropy.
Pdf file