INVESTIGADORES
GANGUI Alejandro
artículos
Título:
The Three-Point Correlation Function of the Cosmic Microwave Background in Inflationary Models
Autor/es:
ALEJANDRO GANGUI; FRANCESCO LUCCHIN; SABINO MATARRESE; SILVIA MOLLERACH
Revista:
ASTROPHYSICAL JOURNAL
Editorial:
University of Chicago Press
Referencias:
Año: 1994 vol. 430 p. 447 - 457
ISSN:
0004-637X
Resumen:
We analyze the temperature three--point correlation function and the skewness
of the Cosmic Microwave Background (CMB), providing general relations in terms
of multipole coefficients. We then focus on applications to large angular scale
anisotropies, such as those measured by the {\em COBE} DMR, calculating the
contribution to these quantities from primordial, inflation generated, scalar
perturbations, via the Sachs--Wolfe effect. Using the techniques of stochastic
inflation we are able to provide a {\it universal} expression for the ensemble
averaged three--point function and for the corresponding skewness, which
accounts for all primordial second--order effects. These general expressions
would moreover apply to any situation where the bispectrum of the primordial
gravitational potential has a {\em hierarchical} form. Our results are then
specialized to a number of relevant models: power--law inflation driven by an
exponential potential, chaotic inflation with a quartic and quadratic potential
and a particular case of hybrid inflation. In all these cases non--Gaussian
effects are small: as an example, the {\em mean} skewness is much smaller than
the cosmic {\em rms} skewness implied by a Gaussian temperature fluctuation
field.