首页 | 本学科首页   官方微博 | 高级检索  
     检索      


Multiple methods for estimating the bispectrum of the cosmic microwave background with application to the MAXIMA data
Authors:M G Santos  A Heavens  A Balbi  J Borrill  P G Ferreira  S Hanany  A H Jaffe  A T Lee  B Rabii  P L Richards  G F Smoot  R Stompor  C D Winant  J H P Wu
Institution:Astrophysics &Theoretical Physics, University of Oxford, Oxford OX1 3RH;Department of Physics, One Shields Ave, University of California, Davis, CA 95616, USA;Institute for Astronomy, University of Edinburgh, Blackford Hill, Edinburgh EH9 3HJ;Dipartimento di Fisica, UniversitàTor Vergata, Roma, Via della Ricerca Scientifica, I-00133 Roma, Italy;Center for Particle Astrophysics, 301 Le Conte Hall, University of California, Berkeley, CA 94720-7304, USA;Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA;National Energy Research Scientific Computing Centre, Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA;Space Sciences Laboratory, University of California, Berkeley, CA 94720, USA;School of Physics and Astronomy, 116 Church St SE, University of Minnesota, Minneapolis, MN 55455, USA;Astrophysics Group, Blackett laboratory, Prince Consort Road, Imperial College, London SW7 2BW;Department of Physics, University of California, Berkeley, CA 94720-7300, USA;Department of Astronomy, 601 Campbell Hall, University of California, Berkeley, CA 94720-3411, USA;Department of Physics, National Taiwan University, No 1 Sec. 4 Roosevelt Road, Taipei 106, Taiwan
Abstract:We describe different methods for estimating the bispectrum of cosmic microwave background data. In particular, we construct a minimum-variance estimator for the flat-sky limit and compare results with previously studied frequentist methods. Application to the MAXIMA data set shows consistency with primordial Gaussianity. Weak quadratic non-Gaussianity is characterized by a tunable parameter   f NL  , corresponding to non-Gaussianity at a level of  ~10?5 f NL  (the ratio of non-Gaussian to Gaussian terms), and we find limits of   f NL= 1500 ± 950  for the minimum-variance estimator and   f NL= 2700 ± 1650  for the usual frequentist estimator. These are the tightest limits on primordial non-Gaussianity, which include the full effects of the radiation transfer function.
Keywords:methods: data analysis  methods: statistical  cosmic microwave background  early Universe
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号