papers

Publications (20)

physics.atom-ph2021

Measurements of blackbody radiation-induced transition rates between high-lying S, P and D Rydberg levels

Matteo Archimi, Matteo Ceccanti, Marco Distefano +7

We report experimental measurements of the rates of blackbody radiation-induced transitions between high-lying (n>60) S, P and D Rydberg levels of rubidium atoms in a magneto-optic…

astro-ph.CO2025

Harmony of the Spheres: Extension to All Points of an Algorithm for Producing a Density Field with Given Two-, Three-, and Four-Point Correlation Functions

Zcahary Slepian, Alessandro Greco

Previous work (Slepian 2024) showed that the Smith-Zaldarriaga (2011) algorithm to realize Cosmic Microwave Background (CMB) maps with any desired harmonic-space bispectrum could b…

astro-ph.CO2025

Cross-correlations of the Cosmic Neutrino Background: HR-DEMNUni simulation analysis

Beatriz Hernández-Molinero, Matteo Calabrese, Carmelita Carbone +3

We use the high-resolution HR-DEMNUni simulations to compute cross-correlations of the Cosmic Neutrino Background quantities, like neutrino density, deflection angle, and velocity,…

astro-ph.CO2025

Measurement of Parity-Violating Modes of the Dark Energy Spectroscopic Instrument (DESI) Year 1 Luminous Red Galaxies' 4-Point Correlation Function

Zachary Slepian, Alex Krolewski, Alessandro Greco +38

Here we report the first measurement of the parity-violating (PV) 4-Point Correlation Function (4PCF) of the Dark Energy Spectroscopic Instrument's Year 1 Luminous Red Galaxy (DESI…

astro-ph.CO2026

First Detection of the Baryon Acoustic Oscillation (BAO) Feature in the 3-Point Correlation Function of DESI DR1 Luminous Red Galaxies

Farshad Kamalinejad, Zachary Slepian, Alex Krolewski +55

We present the first detection of the 3-Point Correlation Function (3PCF) Baryon Acoustic Oscillation (BAO) signal from the DESI Data Release 1 (DR1) sample of Luminous Red Galaxie…

astro-ph.CO2025

Ray-tracing vs. Born approximation in full-sky weak lensing simulations of the MillenniumTNG project

Fulvio Ferlito, Christopher T. Davies, Volker Springel +7

Weak gravitational lensing is a powerful tool for precision tests of cosmology. As the expected deflection angles are small, predictions based on non-linear N-body simulations are…

cond-mat.mtrl-sci2026

A hidden bulk polymorph governs charge transport dimensionality in an organic semiconductor

Caterina Zuffa, Marco Bardini, Fabian Gasser +11

Organic semiconductors (OSCs) are widely explored for flexible optoelectronic technologies, with performance governed not only by molecular design, but also by solid-state packing,…

eess.SP2023

Neural network analysis of neutron and X-ray reflectivity data: Incorporating prior knowledge for tackling the phase problem

Valentin Munteanu, Vladimir Starostin, Alessandro Greco +5

Due to the lack of phase information, determining the physical parameters of multilayer thin films from measured neutron and X-ray reflectivity curves is, on a fundamental level, a…

astro-ph.CO2025

Power Spectrum, Bispectrum, 2- and 3-Point Correlation Function, and Beyond

Zachary Slepian, Farshad Kamalinejad, Alessandro Greco

N-Point Correlation Functions, usually with N = 2, 3, and their Fourier-space analogs power spectrum and bispectrum, are major tools used in cosmology to capture the clustering of…

cs.CV2022

Tracking perovskite crystallization via deep learning-based feature detection on 2D X-ray scattering data

Vladimir Starostin, Valentin Munteanu, Alessandro Greco +6

Understanding the processes of perovskite crystallization is essential for improving the properties of organic solar cells. In situ real-time grazing-incidence X-ray diffraction (G…

astro-ph.CO2025

CMB Lensing Trispectrum as a Probe of Parity Violation in LSS

Alessandro Greco, Zachary Slepian, Jiamin Hou +1

We show that the Cosmic Microwave Background (CMB) lensing trispectrum is sensitive to parity violation in Large-Scale Structure (LSS). We obtain a compact expression for the reduc…

physics.data-an2022

Neural network analysis of neutron and X-ray reflectivity data: automated analysis using mlreflect, experimental errors and feature engineering

Alessandro Greco, Vladimir Starostin, Evelyn Edel +8

This work demonstrates the Python package mlreflect which implements an optimized pipeline for the automized analysis of reflectometry data using machine learning. The package comb…

astro-ph.CO2024

A New Solution for the Observed Isotropic Cosmic Birefringence Angle and its Implications for the Anisotropic Counterpart through a Boltzmann Approach

Alessandro Greco, Nicola Bartolo, Alessandro Gruppuso

Cosmic Birefringence (CB) is a phenomenon in which the polarization of the Cosmic Microwave Background (CMB) radiation is rotated as it travels through space due to the coupling be…

astro-ph.CO2025

Analytic Model for Covariance Matrices of the 2-, 3-, and 4-Point Correlation Functions in the Gaussian Random Field Approximation

Jessica Chellino, Alessandro Greco, Simon May +1

Analyses of the galaxy N-Point Correlation Functions (NPCFs) have a large number of degrees of freedom, meaning one cannot directly estimate an invertible covariance matrix purely…

astro-ph.CO2025

Full Parity-Violating Trispectrum in Axion Inflation: Reduction to Low-D Integrals

Matthew Reinhard, Zachary Slepian, Jiamin Hou +1

Recent measurements of the galaxy 4-Point Correlation Function (4PCF) have seemingly detected non-zero parity-odd modes at high significance. Since gravity, the primary driver of g…

astro-ph.CO2022

Cosmic Birefringence: Cross-Spectra and Cross-Bispectra with CMB Anisotropies

Alessandro Greco, Nicola Bartolo, Alessandro Gruppuso

Parity-violating extensions of Maxwell electromagnetism induce a rotation of the linear polarization plane of photons during propagation. This effect, known as cosmic birefringence…

cond-mat.soft2019

Fast Fitting of Reflectivity Data of Growing Thin Films Using Neural Networks

Alessandro Greco, Vladimir Starostin, Christos Karapanagiotis +6

X-ray reflectivity (XRR) is a powerful and popular scattering technique that can give valuable insight into the growth behavior of thin films. In this study, we show how a simple a…

astro-ph.CO2025

Breaking parity: the case of the trispectrum from chiral scalar-tensor theories of gravity

Tommaso Moretti, Nicola Bartolo, Alessandro Greco

Recently, possible hints of parity violation have been observed in the connected galaxy four-point correlation function. Although the true origin of the signal from the analysis ha…

astro-ph.GA2024

First Measurements of the 4-Point Correlation Function of Magnetohydrodynamic Turbulence as a Novel Probe of the Interstellar Medium

Victoria Williamson, James Sunseri, Zachary Slepian +2

In the Interstellar Medium (ISM), gas and dust evolve under magnetohydrodynamic (MHD) turbulence. This produces dense, non-linear structures that then seed star formation. Observat…

astro-ph.CO2023

Probing Axions through Tomography of Anisotropic Cosmic Birefringence

Alessandro Greco, Nicola Bartolo, Alessandro Gruppuso

Cosmic birefringence is the in-vacuo rotation of the linear polarization plane experienced by photons of the Cosmic Microwave Background (CMB) radiation when theoretically well-mot…