Talks

For n≥3, we demonstrate the existence of quantum codes which are local in dimension n with V qubits, distance V^{(n−1)/n}, and dimension V^{(n−2)/n}, up to a polylog(V) factor. The distance is optimal up to the polylog factor. The dimension is also optimal for this distance up to the polylog factor. The proof combines the existence of asymptotically good quantum codes, a procedure to build a manifold from a code by Freedman-Hastings, and a quantitative embedding theorem by Gromov-Guth.

Zoom link:  https://pitp.zoom.us/j/96227350980?pwd=TEFtamRmTXg3dnBMNEhKUkpHbmVoZz09

In this seminar, I present a study of the electroweak phase transition and baryogenesis in Composite Higgs models. In these scenarios, the Higgs arises from a new, strongly-coupled sector that confines near the TeV scale. The confinement phase transition is described in terms of the dilaton, the pseudo-Nambu-Goldstone boson of broken conformal invariance of the Composite Higgs sector. From the analysis of the joint Higgs-dilaton potential, I show that the electroweak phase transition can naturally be first-order, satisfying one key requirement for electroweak baryogenesis. I then discuss how a sufficient amount of CP violation – another key ingredient of baryogenesis – can be generated from quark Yukawa couplings which vary during the phase transition. Together this setup allows for successful electroweak baryogenesis. This scenario can be tested in complementary ways: in EDM experiments, by searching for dilaton production and deviations in Higgs couplings at colliders, and through gravitational waves at LISA.

In holography, the quantum extremal surface formula relates the entropy of a boundary state to the sum of two terms: the area term and the entropy of bulk fields inside the entanglement wedge. As the bulk effective field theory suffers from UV divergences, the second term must be regularized. It has been conjectured since the work of Susskind and Uglum that the renormalization of Newton’s constant in the area term exactly cancels the difference between different choices of regularization for bulk entropy. In this talk, I will explain how the recent developments on von Neumann algebras appearing in the large N limit of holography allow to prove this claim within the framework of holographic quantum error correction, and to reinterpret it as an instance of the ER=EPR paradigm. This talk is based on the paper arXiv:2302.01938.

Zoom link:  https://pitp.zoom.us/j/97435154387?pwd=OHYrRW9uSW5VeHRFUld1dmtVbmJiZz09