A Caltech Library Service

Cosmological signatures of interacting neutrinos

Bell, Nicole F. and Pierpaoli, Elena and Sigurdson, Kris (2006) Cosmological signatures of interacting neutrinos. Physical Review D, 73 (6). Art. No. 063523. ISSN 2470-0010. doi:10.1103/PhysRevD.73.063523.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


We investigate signatures of neutrino scattering in the cosmic microwave background (CMB) and matter power spectra, and the extent to which present cosmological data can distinguish between a free-streaming or tightly coupled fluid of neutrinos. If neutrinos have strong nonstandard interactions, for example, through the coupling of neutrinos to a light boson, they may be kept in equilibrium until late times. We show how the power spectra for these models differ from more conventional neutrino scenarios, and use CMB and large scale structure data to constrain these models. CMB polarization data improves the constraints on the number of massless neutrinos, while the Lyman-alpha power spectrum improves the limits on the neutrino mass. Neutrino mass limits depend strongly on whether some or all of the neutrino species interact and annihilate. The present data can accommodate a number of tightly coupled relativistic degrees of freedom, and none of the interacting-neutrino scenarios considered are ruled out by current data—although considerations regarding the age of the Universe disfavor a model with three annihilating neutrinos with very large neutrino masses.

Item Type:Article
Related URLs:
URLURL TypeDescription
Bell, Nicole F.0000-0002-5805-9828
Pierpaoli, Elena0000-0002-7957-8993
Sigurdson, Kris0000-0002-6729-0765
Additional Information:© 2006 The American Physical Society. Received 16 November 2005; published 22 March 2006. We thank Matteo Viel for useful discussions and assistance in implementing the Lyman-α data. We thank John Beacom and Scott Dodelson for useful comments on the manuscript. This work was supported in part at Caltech by NASA Grant No. NAG5-9821 and DoE Grant No. DEFG03-92-ER40701. E. P. is supported through the ADVANCE Program (NSF Grant No. AST-0340648), and also by NASA Grant No. NAG5-11489. K. S. acknowledges support at Caltech from the Canadian NSERC and support at the IAS from NASA through Hubble Fellowship Grant No. HST-HF-01191.01-A awarded by the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., for NASA, under Contract No. NAS 5-26555. N. F. B. was supported by the Sherman Fairchild Foundation at Caltech.
Funding AgencyGrant Number
Department of Energy (DOE)DE-FG03-92-ER40701
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
NASA Hubble FellowshipHST-HF-01191.01-A
NASANAS 5-26555
Sherman Fairchild FoundationUNSPECIFIED
Subject Keywords:cosmology; cosmic ray neutrinos; neutrino interactions; neutrino scattering; radiofrequency cosmic radiation; neutrino mass
Issue or Number:6
Record Number:CaltechAUTHORS:BELprd06
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:3935
Deposited By: Lindsay Cleary
Deposited On:19 Jul 2006
Last Modified:08 Nov 2021 20:13

Repository Staff Only: item control page