Talks

In this talk, we identify anomalies of 1+1d lattice Hamiltonian systems as ’t Hooft anomalies. We consider anomalies in internal symmetries as well as Lieb-Schultz-Mattis (LSM) type anomalies involving lattice translations. Using topological defects, we derive a simple formula for the ‘anomaly cocycle’ and show it is the obstruction to gauging even on the lattice. We reach this by introducing a systematic procedure to gauge arbitrary internal symmetries on the lattice that may not act on-site. As a by-product of our gauging procedure, we construct non-invertible lattice translation symmetries from LSM anomalies.

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Zoom link https://pitp.zoom.us/j/98084408560?pwd=cllSVnpWcEhPK21aVDZubU4yYWNyQT09

I will present work on probing the large scale structure of the universe using CMB lensing from the upcoming Data Release 6 of the Atacama Cosmology Telescope (ACT) and cross-correlations with galaxies from the unWISE galaxy catalog. My talk will focus on how our highly competitive constraints from CMB lensing and CMB lensing cross-correlations can provide insight into the widely discussed “S8/sigma8 tension”. For this purpose I will briefly introduce the high fidelity CMB lensing reconstruction obtained by the ACT Collaboration and results from the analysis of the lensing auto-correlation. I will discuss new results from the cross-correlation between ACT CMB lensing and unWISE galaxies, highlighting improvements to the analysis pipeline compared to previous work on the cross-correlation between Planck CMB lensing and unWISE by some of my collaborators (Krolewski et al. 2021). I will also show a reanalysis of Planck CMB lensing x unWISE and a joined analysis of the ACT and Planck CMB lensing cross-correlations with unWISE.

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Zoom link https://pitp.zoom.us/j/99192611116?pwd=TU9iMjhrejVESjNRdi92M0ZXN2ZEQT09

This session will introduce the grad student seminar series, include an interactive session focusing on thoughts and ideas for effective preparation and presentation, and will gauge students' interest about upcoming science outreach activities.

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Zoom link https://pitp.zoom.us/j/95397824623?pwd=LzViSVBpTXJzcjZXbjlhdzZKMk9Ndz09

What relations are there between the various ways of wrangling with quantum gravity? String theory is now much more than just a theory of strings -- branes and braneworlds abound. Some kind of effective theory for the familiar world needs to emerge. Are there ways that one could glimpse underlying structure from aspects of an effective theory? That happens for pions -- is there anything like that for gravity? Effective theories also involve higher derivatives, and those can summon up spirits (i.e. ghosts) from the vasty deep. Do asymptotic freedom or asymptotic safety give ways to exorcise them? And what might the effective theory tell us about the earliest times?

Numerical simulations of collision events within the ATLAS experiment have played a pivotal role in shaping the design of future experiments and analyzing ongoing ones. However, the quest for accuracy in describing Large Hadron Collider (LHC) collisions comes at an imposing computational cost, with projections estimating the need for millions of CPU-years annually during the High Luminosity LHC (HL-LHC) run. Simulating a single LHC event with Geant4 currently devours around 1000 CPU seconds, with calorimeter simulations imposing substantial computational demands. To address this challenge, we propose a Quantum-Assisted deep generative model. Our model marries a variational autoencoder (VAE) on the exterior with a Restricted Boltzmann Machine (RBM) in the latent space, delivering enhanced expressiveness compared to conventional VAEs. The RBM nodes and connections are meticulously engineered to enable the use of qubits and couplers on D-Wave's Pegasus Quantum Annealer. We also provide preliminary insights into the requisite infrastructure for large-scale deployment.

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Zoom link https://pitp.zoom.us/j/97724484247?pwd=Witua1lKcHlrc3JDNHNDWXpHYkVvQT09