Seminario di Fenomenologia

Feedback from active galactic nuclei and stellar processes changes the matter distribution on small scales, leading to significant systematic uncertainty in weak lensing constraints on cosmology. In this talk, I will describe how the observable properties of group-scale halos can be used to constrain the impact of feedback on the matter distribution using Cosmology and Astrophysics with Machine Learning Simulations (CAMELS). By extending the results of previous work to smaller halo masses and higher wave numbers, k, we find that the baryon fraction in halos contains valuable information about the impact of feedback on the matter power spectrum. We will also explore how the thermal Sunyaev Zel’dovich (tSZ) signal from group-scale halos can provide similar information. Using recent Dark Energy Survey (DES) weak lensing and Atacama Cosmology Telescope (ACT) tSZ cross-correlation measurements and models trained on CAMELS, we obtain 10% constraints on the effects of feedback on the power spectrum at k ~ 5 h/Mpc. I will also demonstrate that with future surveys, it will be possible to constrain baryonic effects on the power spectrum to O(<1%) at k = 1 h/Mpc and O(3%) at k = 5 h/Mpc using the methods introduced here.
Per connettersi a zoom:
Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fenomenologia

I present the first clear evidence for the presence of an intrinsic charm component in the proton. I recall the meaning of intrinsic charm and how intrinsic and perturbative charm can be distinguished from each other. I briefly review the NNPDF4.0 determination of the structure of the proton, and I discuss how its results, together with recent advanced tools for the evolution and matching of parton distributions, can be used for a separation of the perturbative and intrinsic charm components and a determination of the latter. I present results for the intrinsic charm component, I compare them to models, I discuss which current data have animpact on it, and briefly examine ongoing future improvements of the current result.

Per connettersi a zoom:

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fenomenologia

In this talk I will consider signal-background interference effects in Higgs-mediated diphoton production at the LHC. The inclusion of such effects results in a shift of the diphoton invariant mass distribution and in a destructive contribution to the total cross section. As pointed out in earlier works, one can exploit interference studies to put bounds on the Higgs boson decay width. After reviewing the Higgs interferometry framework I will present an extension of this analysis up to NNLO QCD in the soft-virtual approximation.

Per connettersi a zoom:

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fenomenologia –

Machine Learning is, in most cases, powerful but a black-box application. In this talk, we will tackle this very problem from a quantum mechanics point of view, arguing that an optimisation problem, such as classification or anomaly detection, can be studied by “rephrasing” the problem as a quantum many-body system or a mixed state. Such an approach allows us to employ the entire arsenal of quantum theory for data analysis techniques while enabling exact representation for a quantum device. Hence this talk will present a small step towards fully theory-driven and interpretable quantum machine learning applications.

Per connettersi a zoom:—

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fenomenologia –

The stochastic gravitational waves background is a rich resource of cosmological information, encoded both in its source statistics and its anisotropies. During their journey, the gravitational waves constituting the background encounter cosmic structures, which are able to modify the observed signal. According to the ratio between the wavelength of the wave, and the matter overdensities typical length-scale, interference and diffraction effects may arise, possibly boosting the signal’s amplitude or inducing a non-trivial polarization pattern. In this talk I will present results about the wave-optics limit of the stochastic gravitational wave background, and describe how we can use them to gain information about the matter content of the Universe.

Per connettersi a zoom:

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271Meeting ID: 857 318 5271

Seminario di Fisica Teorica –

I will present the classification of all unitary, rational conformal field theories with one non-trivial primary and central charge c < 25. (with Brandon Rayhaun, arXiv: 2208.05486). I will also, more briefly, review a partial classification of theories with two nontrivial primaries, as well as some new predictions on the existence of meromorphic CFT with central charge 32.

Per connettersi a zoom:

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fisica Teorica –

Hydrodynamics is the effective theory that governs the transport of charge, energy and momentum at late times and large distances. In certain circumstances this description must be modified to include the fact that these charges decay very slowly; for example when there are chemical processes or spatial translation invariance is broken. In this talk I will primarily discuss how to incorporate such “relaxation” processes into the effective theory of a fluid driven by an electric field. Given sufficient time I will place this work in the larger context of the relaxed hydrodynamics programme and tease new results.

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fenomenologia –

Axion-like particles (ALPs) are one of the most attractive solutions to the dark matter issue.

In this talk, I will discuss how to search for ALPs in astrophysical structures.

After some introduction, I will focus on the emission associated with their decay into photons.

The discussion will involve different ALP mass ranges and wavelength bands.

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fisica Teorica –

This talk revolves about low-energy effective field theories with fractonic degrees of freedom characterised by mobility constraints. The fractonic features descend from spatially-dependent rigid symmetries, like sub-system symmetries and multipole symmetries. We focus mainly on the emergence of fractonic dynamics in standard elastic theory and generalization thereof. Elastic defects behave at low energy as fractons and they can be described as the charged objects of a dual gauge theory through Hubbard-Stratonovich duality. We propose to formulate such dual gauge theory purely in terms of standard vector gauge fields, as opposed to the customary formulation in terms of tensor gauge fields. The new formulation is promising in view of addressing some fundamental open questions related to the coupling of fractonic theories to a background geometry, relevant for their theoretical consolidation as well as for applications. If time allows, we also comment on the relation of fractons with dynamical breaking of translation symmetry and the possibility to UV complete some known fractonic models.

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271

Seminario di Fenomenologia –

General-purpose Monte Carlo event generators are omnipresent in collider physics. As an introduction, I will discuss the various building blocks entering such tools. The talk will focus on the core part, the so-called parton-shower algorithm. I will what it is meant to achieve, i.e. connections with all-order calculations in perturbative QCD, and how it does it in practice, i.e. (usually) as a dipole shower. The main part of the talk will, describe the effort of the PanScales collaboration in order to improve the current state-of-the-art.

Topic: Theory and Pheno seminars

https://infn-it.zoom.us/j/8573185271

Meeting ID: 857 318 5271