INFLATION, DARK MATTER, AND THE LARGE-SCALE STRUCTURE
OF THE UNIVERSE


The goal of this research project is to investigate
the interconnection between particle physics and
crucial aspects of the standard Big-Bang cosmological
model. In particular, we are actively investigating aspects of inflation in the Early Universe, the nature of dark matter and dark energy. Particular emphasis is given to
the present-day and future observations of the Cosmic
Microwave Background (CMB) radiation, the study of the Large-Scale Structure (LSS) of the Universe and the
indirect signatures of DM candidates coming from future experiments.


1) INFLATION: THEORETICAL PREDICTIONS AND OBSERVATIONAL TESTS

We investigate the testable predictions of
inflationary models of the early Universe and their
feedback on particle-physics models.
We focus on:
- inflationary models and particle-physics, with
particular emphasis on supersymmetry and theories with
extra-dimensions (brane-world);
- nature (adiabatic and/or isocurvature), statistics
(Gaussian or non-Gaussian) and spectral properties of
density perturbations produced by vacuum oscillations
during inflation; spectral properties of the stochastic
gravitational-wave background generated by quantum
fluctuations of the metric during inflation.

Observations of CMB anisotropies (both from present-day
and ongoing experiments, such as BOOMERanG, MAXIMA-I,
DASI, CBI, ARCHEOPS, WMAP, etc., and future ones, such as Planck), as well as investigations of the LSS of the Universe from existing and future large galaxy surveys
(such as 2dF, SDSS, etc.) will provide accurate
determinations of cosmological parameters, including
those more relevant for particle-physics.
We focus on:
- CMB: determination of inflaton potential parameters
(slow-roll parameters via constraints on scalar and
tensor spectral indices, tensor/scalar ratio, etc...)
and study of possible signatures of physics beyond the
standard model (e.g. CP violation, primordial magnetic
fields, etc..)
- LSS: complementary tests coming from statistics of
large galaxy redshift surveys, analysis of galaxy
cluster datasets, study of Ly-alpha forest in quasar absorption spectra, etc..

2) DARK MATTER AND DARK ENERGY: ASTROPHYSICAL AND COSMOLOGICAL ASPECTS

We study the astrophysical and cosmological
properties of dark matter (DM) and dark energy; their
influence on the formation of structure (from galaxy
halos to LSS) and on CMB anisotropies.
We focus on:
- particle-physics properties of DM candidates as inferred from their distribution at different scales;
- DM distribution in galaxy halos and consequences
for DM search experiments;
- theoretical predictions of indirect signatures of
DM candidates, in connection with future experiments
such as PAMELA, AGILE and GLAST;
- cosmological and particle physics properties of dynamical dark energy models.

A particular aspect of our activity concerns
training students and young researchers in the area
of astroparticle physics in collaboration with
the Scuola Normale Superiore in Pisa.
Within this activity we have so far organized:
1) the `Pisa Seminar on Astroparticle Physics and Cosmology' (Spring 2003); 2) the `Pisa Seminar on Radiations in the Universe' (fall 2003); 3) the `Pisa Seminar on new directions in Physics beyond the Standard Model' (Spring 2004); 4) the "Cosmic Connections" meeting in Quarrata - in collaboration with UCLA - (May 2005).