High Energy Physics

A black hole quantum state (Hartle-Hawking or Boulware)  is usually defined in a fixed background of a classical black hole. In my talk I will discuss the corresponding space-time geometry when the back-reaction is taken into account. The important questions include: does the back-reacted geometry always contain a horizon?; how it depends on the choice of the quantum state?;  and what is the right choice for the quantum state for the non-physical fields such as ghosts? I will answer these and other questions in the context of a two-dimensional dilaton gravity. The talk is based on a joint recent work with D. Sarkar and Y. Potaux, arXiv:2112.03855.

Zoom Link: https://pitp.zoom.us/j/5053597405?pwd=YjU2VVF1L3A1dmR1VWpPMHZFQW9rdz09

Three dimensional conformal field theories(CFTs) describe important critical physics in the real world. In the past few years much progress has been made in 3D CFTs using the conformal bootstrap. In particular, using numerical bootstrap, the critical exponents of the 3D Ising, Super-Ising, O(2), O(3) CFTs have been determined precisely with rigorous error bars, while using analytic bootstrap, the information of the leading twist operators at large spins can be computed analytically. The two bootstrap approaches are sensitive to different regions of the spectrum and complement each other. In this talk, I will first give a general review of the numerical bootstrap and analytic bootstrap. Then I will discuss how to combine the numerical bootstrap with the analytic lightcone bootstrap, i.e. a hybrid bootstrap method. As a result, the bootstrap prediction for the actual CFT can be significantly improved.

Zoom Link: https://pitp.zoom.us/j/94186668943?pwd=ejRRb0M4VXNjeVVCWGdnTHQyaWRyQT09

There are two different standard ways of endowing a physical theory with a symplectic structure: the canonical and the covariant. The former is derived from the well-known symplectic structure of a certain cotangent bundle. The latter is based on the variational calculus. Including a boundary in the canonical formalism poses no problem, however, in the covariant formalism things break apart. In this talk, I will briefly introduce both formalisms without boundary and explain in detail a new framework that allows us to include boundaries in a straightforward way. To show it in action, time permitting, I will apply it to several theories of gravity. Finally, I will briefly show a new result where we proved that, actually, the canonical and covariant formalisms are equivalent in full generality.

Zoom Link: https://pitp.zoom.us/j/97641588140?pwd=dFl0SFdHOG5BYko2djNVWk11UkhSUT09

Mirror symmetry and time-invariance violating processes were crucial at establishing the Standard Model of fundamental interactions as we know it, their tiny effects eventually measured after enormous experimental effort. Macroscopic material on the other hand can maximally break these symmetries spontaneously. Inside these materials, Dark Matter can exhibit phenomena otherwise impossible in the vacuum. In this talk, I will discuss such a phenomenon that we call the piezoaxionic effect: In crystals whose structure breaks mirror symmetry, which are broadly known as piezoelectric, dark matter candidates called axions will produce a change in the crystals size, i.e. strain. Such a strain can be detected with well-established methods leading to a new observable for this well-motivated class of Dark Matter candidates.

Zoom Link: https://pitp.zoom.us/j/96153495346?pwd=QU1MTENUTzdNOU5sZVc3VzY4NHI1UT09

Holographic complexity proposals are interesting because, on one hand, they express universal properties of black hole interiors and, on the other, they go beyond the area-centric view on quantum gravity. Our best take on complexity in quantum field theory is based on assigning a cost to circuits generated by time-dependent Hamiltonians and its minimization. I will discuss recent progress on understanding how the relevant circuits are realized in holography and what are possible gravity duals to good costs. Based on 2112.12158, 2203.08842 and work in progress.

Zoom Link: https://pitp.zoom.us/j/96487059058?pwd=ZHk1ZHpXMEZoT0UycUZqTEdIb1ZpQT09

In this talk, I will present MicroBooNE's first results probing the nature of the excess of low-energy interactions observed by the MiniBooNE collaboration. The talk will cover all four electron neutrino analyses that comprise MicroBooNE's first results, with a particular focus on the exclusive search for CCQE-like electron neutrino interactions containing one electron and one proton in the final state (1e1p). The result of the 1e1p analysis, along with results from the other electron analyses and the single-photon analysis, will be discussed in terms of their implications for the MiniBooNE excess. Specifically, I will examine the viability of the single sterile neutrino explanation of the MiniBooNE excess in light of the MicroBooNE electron neutrino results. Additionally, I will introduce the Coherent CAPTAIN-Mills (CCM) experiment at Los Alamos National Laboratory. CCM has unique sensitivity to a number of exotic BSM models, including leptophobic vector-portal dark matter and axion-like particles, some of which may be able to explain the MiniBooNE anomaly.

Zoom Link: https://pitp.zoom.us/j/93290406752?pwd=ajIvZkhvVU5YMW90WjVpU3IySUphdz09

Higher dimensional models of black hole evaporation can be studied via double holographic constructions, which can be considered as holographic models of conformal interfaces. In string theory these are realized microscopically by appropriate systems of branes, and in particular limits they give rise to a light graviton mass in the effective gravity theory. For a specific model of D3-D5-NS5 branes in type IIB, I will discuss the properties of the lightest graviton and show how this constrains the existence of islands in Anti de Sitter. I will show a numerical study of islands surfaces for finite temperature black holes, and show how they are affected by a varying dilaton. I will finally comment on the EFT cutoff induced by a light graviton mass, in relation to the islands regime, in function of the microscopic parameters of the string theory construction.

Zoom Link: https://pitp.zoom.us/j/97993595112?pwd=dE1xRm42MmY3bEVYZ2c4VURtaWV4dz09

Based on 2203.09537. In the context of toy models of holography arising from 3d Chern-Simons theory, I will describe an approach in which, rather than summing over bulk geometries, one gauges a one-form global symmetry of the bulk theory. This ensures that the bulk theory has no global symmetries, and it makes the partition function on spacetimes with boundaries coincide with that of a modular-invariant 2d CFT on the boundary. In particular, on wormhole geometries one finds a factorized answer for the partition function.

Zoom Link: https://pitp.zoom.us/j/91694973383?pwd=VWFCZWxtdy9GczUrN1JFc2xMVUhmdz09

I will discuss the large-N limit of two-dimensional symmetric product orbifolds. The goal is to single out which symmetric product orbifold theory could lead to a strongly coupled theory, whose dual could be a semi-classical theory of AdS_3 gravity, by quantifying the large-N limit of the BPS spectrum and the behaviour under exactly marginal deformations. From this analysis, I will propose an infinite family of new holographic CFTs.

Zoom Link: https://pitp.zoom.us/j/99948208493?pwd=RDRYclc2a05kMmNZL3ZhMWxMdWdNUT09

Muons are the archetypal ‘who ordered that?’ surprise discovered in cosmic rays and fittingly, recent muon measurements including g–2 could be challenging standard paradigms again. Remarkably, tau g–2 remains poorly constrained but can be 280 times more sensitive to new physics than the muon. Recently, ATLAS and CMS announced groundbreaking measurements of tau g–2 using the landmark observation of tau pairs created via photon collisions in LHC heavy-ion data. Beyond colliders, quantum sensing progress enables next-generation haloscopes to illuminate axion-like origins of dark matter above microwave frequencies. This motivates the Broadband Reflector Experiment for Axion Detection (BREAD) proposal at Fermilab and its interdisciplinary science program bridging astronomy, particle physics, and quantum technology.

Zoom Link: https://pitp.zoom.us/j/95937524952?pwd=eFVaTXVXOHBiNE9TZk9oMGNxRUwyQT09

We suggest a framework for cosmology based on gravitational effective field theories with a negative fundamental cosmological constant, which may exhibit accelerated expansion due to the positive potential energy of rolling scalar fields. The framework postulates an exact time-reversal symmetry of the quantum state (with a time-symmetric big bang / big crunch background cosmology) and an analyticity property that relates cosmological observables to observables in a Euclidean gravitational theory defined with a pair of asymptotically AdS planar boundaries. The latter can be given a microscopic definition using holography, so the model is UV complete. While it is not yet clear whether the framework can give realistic predictions, it has the potential to resolve various naturalness puzzles without the need for inflation.

Zoom Link: https://pitp.zoom.us/j/95099004342?pwd=OWZoanJJMHNzMXF4S3VYM2Vxcklodz09

The volume of the interior of a two-sided eternal black hole classically grows forever. I will derive a microscopic formula for this volume in JT gravity by summing the non-perturbative contribution of higher topologies. The non-perturbative corrections lead to the saturation of the volume of the interior at times exponential in the entropy of the black hole. I will connect the microscopic formula for the volume with properties of a "thermo-averaged" density matrix, in particular with its second Renyi entropy, which I argue to measure the number of nearly orthogonal states visited by time evolution. I will discuss various problems with this interpretation.

Zoom Link: https://pitp.zoom.us/j/99880539557?pwd=VWZiMFI5Rk5pdnNZRE5kalRvUk1Zdz09