The marked two-point correlation function, which is particularly sensitive to the surrounding environment, offers a promising approach to enhancing the discriminating power in clustering analyses and to potentially detecting modified gravity (MG) signals. In this talk I will present my work that investigates novel marks based on large-scale environment estimates, which also exploit the...
The Baryon Acoustic Oscillations (BAOs) scale in the 2-point galaxy correlation function serves as a standard ruler to trace the expansion history of the Universe and constrain the properties of the Dark Energy, as demonstrated by the recent results of the DESI survey. Precise measurements of the BAO scale rely on nonlinear transformation of the data commonly known as “reconstruction”. The...
The latest generation of spectroscopic surveys, such as DESI, Euclid or Subaru-PFS, aims to map the large-scale structure of the Universe with unprecedented accuracy by targeting diverse galaxy populations: luminous red galaxies (LRGs), emission-line galaxies (ELGs), and quasars (QSOs). These sources serve as biased multi-tracers of the underlying dark matter field, and their clustering...
Indicator functions identify regions of a given density characterizing the density dependence of clustering. I show that indicator-function power spectra are biased versions of the linear spectrum on large scales. A first principle calculation for this bias reproduces simulation results. I provide a simple functional form for the translinear portion of the indicator-function spectra. These...
The clustering of large scale structure has been recognised as a fundamental cosmological probe, which offers us the possibility to constrain fundamental parameters, such as the matter density content of the Universe. Currently, the most acknowledged cosmological scenario is the $\Lambda$CDM model, which assumes that dark matter particles exist in a ‘cold' version, namely in the form of very...
In this talk, I will explore the potential of de-noising large cosmological covariance matrices using analytical techniques from Random Matrix Theory, particularly the class of Rotational Invariant estimators. I will evaluate the performance of this approach using galaxy clustering statistics and I will compare them with non-linear shrinkage methods, highlighting their advantages and limitations.
In this talk, we present, for the first time, cosmological parameter constraints obtained by jointly analysing the two-point correlation function (2PCF) and the three-point correlation function (3PCF). This work marks the final step of a research programme which, over the past few years, has bridged the gap between configuration space and Fourier space, both in terms of observational...
Understanding the large-scale distribution of galaxies often relies on two-point statistics—either the configuration-space two-point correlation function or its Fourier-space counterpart, the power spectrum. Although these measures are theoretically equivalent, practical estimates can lead to subtle differences that impacts the cosmological interpretation of the results.
In this talk, I...
With the present and upcoming Stage IV spectroscopic surveys, soon we will have data of more than a billion galaxies. This enables us to move beyond traditional two-point statistics to explore higher-order correlations. In particular, the three-point correlation function (3PCF) offers many advantages – it can probe non-Gaussianity, break degeneracies between cosmological parameters, and...
The large-scale distribution of galaxies contains information about the acoustic waves propagated in the primordial baryon-photon plasma. These waves imprint a characteristic scale in the two point correlation function of the galaxies. This scale, called Linear Point, is defined as the mid-point between the maximum and the minimum of the correlation function at scales of about 150 Mpc.
In my...
