Speakers
Marija Tomašević
CERN
Dressing up naked singularities
Abstract: Small naked singularities—those not shielded by a macroscopic event horizon—are ubiquitous in classical General Relativity. Their existence constitutes apparent violations of the weak cosmic censorship conjecture, which asserts that physically reasonable solutions should appear regular to asymptotic observers. In this talk, we will show how the inclusion of stringy and quantum effects resolves these pathologies by uplifting naked singularities into fully regular configurations. Focusing on critical gravitational collapse as a concrete example, we demonstrate that a proper quantum treatment replaces naked singularity formation with black hole formation. This suggests that cosmic censorship is not fundamentally a property of classical General Relativity, but rather emerges only once quantum gravitational effects are taken into account.
Jonathan Heckman
University of Pennsylvania
¿What is an R7-Brane?
Abstract: The Swampland Cobordism conjecture asserts that in quantum gravity, any spacetime can terminate, i.e., the cobordism group of quantum gravity is trivial. A striking consequence of this conjecture is that it predicts the existence of previously unknown non-supersymmetric stable objects in gravity. In type IIB string theory, this leads to a new class of branes now known as reflection 7-branes (R7-branes). We present both some topological features of these solutions, as well as the corresponding gravitational backgrounds these sources generate. This bulk gravity analysis also provides strong evidence for the existence of a novel 8D quantum field theory localized on the worldvolume of the brane.
Ibrahima Bah
Johns Hopkins University
Title
Monica Jinwoo Kang
Texas A&M University
Purely GHZ-like Entanglement is Forbidden in Holography
Abstract: Entanglement is the fundamental feature of quantum systems. While bipartite entanglement can be computed precisely as a physical measure via entanglement entropy, the Greenberger-Horn-Zeilingert structure requires much more difficulty. I will explain how to understand the multiparty entanglement, devise physical quantities that signals multiparty entanglement. I will focus on a particular result that from utilizing these signals, we deduce crucial novel discovery on the entanglement structure special in holography that the purely Greenberger-Horn-Zeilinger (GHZ)-like entanglement is forbidden in holography, thereby disproving a conjecture established by Susskind and others.