Non-Gaussianities in models with a varying inflaton decay rate

被引:172
作者
Zaldarriaga, M [1 ]
机构
[1] Harvard Univ, Dept Astron, Cambridge, MA 02138 USA
[2] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA
来源
PHYSICAL REVIEW D | 2004年 / 69卷 / 04期
关键词
D O I
10.1103/PhysRevD.69.043508
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We consider the expected level of primordial non-Gaussianities in models in which density perturbations are produced by spatial fluctuations in the decay rate of the inflaton. We consider non-Gaussianities resulting from the self-coupling of the field that controls the decay rate of the inflaton and non-Gaussianities resulting from the nonlinear relation between field and curvature perturbations. We show that in these scenarios non-Gaussianities are of the "local" form, i.e., well described by the ansatz R=R-g+f(NL)(R)(R-g(2)-<R-g(2)>). This is a consequence of the fact that they were created when modes were already outside the horizon. We show that f(NL)(R) is naturally of the order of a few in these models, much larger than what is expected in the standard one field models of inflation (f(NL)(R)similar to10(-2)) and possibly accessible to observations.
引用
收藏
页数:7
相关论文
共 24 条
[1]   Gauge-invariant second-order perturbations and non-Gaussianity from inflation [J].
Acquaviva, V ;
Bartolo, N ;
Matarrese, S ;
Riotto, A .
NUCLEAR PHYSICS B, 2003, 667 (1-2) :119-148
[2]   Non-Gaussianity from inflation [J].
Bartolo, N ;
Matarrese, S ;
Riotto, A .
PHYSICAL REVIEW D, 2002, 65 (10)
[3]   Oscillations during inflation and the cosmological density perturbations [J].
Bartolo, N ;
Matarrese, S ;
Riotto, A .
PHYSICAL REVIEW D, 2001, 64 (08)
[4]   First-year Wilkinson Microwave Anisotropy Probe (WMAP) observations:: Preliminary maps and basic results [J].
Bennett, CL ;
Halpern, M ;
Hinshaw, G ;
Jarosik, N ;
Kogut, A ;
Limon, M ;
Meyer, SS ;
Page, L ;
Spergel, DN ;
Tucker, GS ;
Wollack, E ;
Wright, EL ;
Barnes, C ;
Greason, MR ;
Hill, RS ;
Komatsu, E ;
Nolta, MR ;
Odegard, N ;
Peiris, HV ;
Verde, L ;
Weiland, JL .
ASTROPHYSICAL JOURNAL SUPPLEMENT SERIES, 2003, 148 (01) :1-27
[5]   Inflationary models inducing non-Gaussian metric fluctuations [J].
Bernardeau, F ;
Uzan, JP .
PHYSICAL REVIEW D, 2003, 67 (12)
[6]   Non-Gaussianity in multifield inflation [J].
Bernardeau, F ;
Uzan, JP .
PHYSICAL REVIEW D, 2002, 66 (10)
[7]   Large-scale structure of the Universe and cosmological perturbation theory [J].
Bernardeau, F ;
Colombi, S ;
Gaztañaga, E ;
Scoccimarro, R .
PHYSICS REPORTS-REVIEW SECTION OF PHYSICS LETTERS, 2002, 367 (1-3) :1-248
[8]  
DVALI G, ASTROPH0305548, P43527
[9]  
DVALI G, ASTROPH0303591
[10]   Adiabatic CMB perturbations in pre-Big-Bang string cosmology [J].
Enqvist, K ;
Sloth, MS .
NUCLEAR PHYSICS B, 2002, 626 (1-2) :395-409