641 Works

Q&A with the day’s speakers - August 11

Q&A with the day’s speakers - August 10

Computational methods: (Now with data)

Moduli Stabilization and Holographic RG

In this talk, I will relate moduli stabilization in AdS or de Sitter space to basic properties of the Wilsonian action in the holographic dual theory living on dS (of one lower dimension):  the single-trace terms in the action have vanishing beta functions, and higher-trace couplings are determined purely from lower-trace ones (a property we refer to as the iterative structure of RG).  In the dS case, this encodes the maximal symmetry of the bulk...

Tomography on the Sphere

a short presentation about work characterizing triphoton states via Wigner functions on the Poincaré sphere.

A new approach to Quantum Estimation: Theory and Applications

A new approach to Quantum Estimation Theory will be introduced, based on the novel notions of \'quantum comb\' and \'quantum tester\', which generalize the customary notions of \'channel\' and \'POVM\' [PRL 101 060401 (2008)]. The new approach opens completely new possibilities of optimization in Quantum Estimation, beyond the classic approach of Helstrom and Holevo. Using comb theory it is possible to optimize the input-output arrangement of the black boxes for estimation with many uses. In...

Interferometry and the Global 21-cm Signal

The global redshifted 21-cm radiation background is expected to be a powerful probe of the re-heating and re-ionization of the intergalactic medium. However, its measurement is technically challenging: one must extract the small, frequency-dependent signal from under much brighter and spectrally smooth foregrounds. Traditional approaches to study the global signal have used single-antenna systems, where one must calibrate out frequency-dependent structure in the overall system gain, as well as remove the noise bias from auto-correlating a...

Fast radio bursts as probes of large-scale structure

Fast radio bursts (FRBs) are bright, broadband, non-repeating, millisecond flashes of unknown astronomical origin. The dispersion of these bursts by intervening plasma suggests that the sources of the 16 bursts reported to date= are at 0.2<z<1. I will discuss the possibility of using dispersion, instead of redshift, to study the large-scale structure of the Universe in three dimensions. Like redshift, which is distorted by peculiar velocities, dispersion is an imperfect proxy for distance as it...

Cluster Structures on Higher Teichmuller Spaces for Classical Groups - Ian Le

Let $S$ be a surface, $G$ a semi-simple group of type B, C or D. I will explain why the moduli space of framed local systems $A_{G,S}$ defined by Fock and Goncharov has the structure of a cluster variety, and fits inside a larger structure called a cluster ensemble. This was previously known only in type A. This gives a more direct proof of results of Fock and Goncharov for the symplectic and spin groups,...

Tensor renormalization group in bosonic field theory

We compute the partition function of a massive free boson in a square lattice using a tensor network algorithm. We introduce a singular value decomposition (SVD) of continuous matrices that leads to very accurate numerical results. It is shown the emergence of a CDL fixed point structure. In the massless limit, we reproduce the results of conformal field theory including a precise value of the central charge.

Irreducible flavour and CP violation in SUGRA flavour models

In SUGRA flavour models, a total sequestering is not possible and an irreducible amount of flavour and CP violation is essentially unavoidable, which renders many flavour models testable in the near future experiments.

F-theory and GUTs: Experimental Predictions

Status of EXO-200

Searches for neutrinoless double beta decays could determine if neutrinos are Majorana particles and could measure their absolute mass scale. The initial stage of the Enriched Xenon Observatory project, EXO-200, will look for two-neutrino and neutrinoless double-beta decays of Xe-136 in a liquid-xenon time-projection chamber. By combining the ionization signal with detection of the scintillation light collected in Large Area Avalanche Photodiodes (LAAPDs), an energy resolution of about 1.4% at the decay energy can be...

The anthropic solution to the strong CP problem and its cosmological implications.

We point out that the strong CP problem can be resolved by the anthropic principle. The key ideas are to allow explicit breaking(s) of the Peccei-Quinn symmetry which connects the problem to the cosmological constant problem, and to conjecture that the probability distribution of the vacuum energy in the landscape is hierarchical. The axion acquires a large mass from the explicit breaking, and does not contribute to the dark matter abundance. The axion may dominate...

SKT Geometry

In classical terms, an SKT structure is a Hermitian structure for which the Hermitian 2-form is closed with respect to the second order operator ddc. These structures arise naturally in the study of sigma models with (2; 0) or (2; 1)-supersymmetries, much like generalized Kahler structures arise in the (2; 2)-supersymmetric sigma model. While the introduction of generalized complex geometry has provided the correct framework to study generalized Kahler structures and great progress has been...

Complex Manifolds


Complex manifolds


LIGO: Astronomical Observatory and Physics Playground

Testing inflation with combined power- and bispectrum

Evolving Laws: Chapter 2 - Jaron Lanier's opening statement

Constancy has been thought to exist in situations where in fact it did not;
The concept of computation.

Inflationary spectra and violation of Bell inequalities

We point out that there exit operators, having a clear meaning in cosmology -- they select a given realization of the distribution of primordial density fluctuations --, which can violate Bell inequalities when evaluated in the ''standard'' inflationary quantum distribution. We then consider density matrices which describe partially decohered distributions and show how the importance of the violation decreases with the decoherence level. We determine the critical level beyond which no violation can be obtained....

3D Digital Holographic Interferometry: Applications in Biomedicine

Digital Holographic Interferometry (DHI) plays an important role in the evaluation of object static and dynamic displacements. The state of the art research on this technique is such that it is being used to solve problems in a wide variety of disciplines, from basic Physics to engineering and even social sciences. This invited plenary talk will deal with specific applications in some biomedical objects, even showing preliminary results using Electron Holography.

Registration Year

  • 2022

Resource Types

  • Audiovisual


  • Perimeter Institute