WMAP - Second Release Options

[antoniseb]

Some discussion of the yet to be released WMAP Second Data Release has been going on elsewhere on this forum. I've created this thread as a better labelled place for such discussion.

I have been writing that the second release is overdue, and that there are some hints that there are unexpected things that have contaminated the first release data. Others have pointed out that the data is not clear and needs a lot of time to resolve.

[The Messenger]

Any news from the Latin-American AIU meeting? There was a Lyman Page presentation on "Recent WMAP Results" scheduled:

http://www.larim2005.cl/index.php?value=program

[ljk4-1]

Paper: astro-ph/0601004

Date: Sat, 31 Dec 2005 06:36:19 GMT (24kb)

Title: Relic keV sterile neutrinos and reionization

Authors: Peter L. Biermann and Alexander Kusenko

Comments: 4 pages, 2 figures

Report-no: UCLA/05/TEP/35
\\
A sterile neutrino with mass of several keV can account for cosmological dark
matter, as well as explain the observed velocities of pulsars. We show that
X-rays produced by the decays of these relic sterile neutrinos can boost the
production of molecular hydrogen, which can speed up the cooling of gas and the
early star formation, which can, in turn, lead to a reionization of the
universe at a high enough redshift to be consistent with the WMAP results.

\\ ( http://arXiv.org/abs/astro-ph/0601004 , 24kb)

[ljk4-1]

Paper: astro-ph/0601095

Date: Thu, 5 Jan 2006 11:57:43 GMT (65kb)

Title: Searching For CPT Violation With WMAP And BOOMERANG

Authors: Bo Feng, Mingzhe Li, Jun-Qing Xia, Xuelei Chen and Xinmin Zhang

Comments: 4 pages, 3 figures Revtex4

Report-no: RESCEU-2-06
\\
We search for signatures of Lorentz and $CPT$ violations in the cosmic
microwave background(CMB) temperature and polarization anisotropies by using
the first year WMAP and the 2003 flight of BOOMERANG(B03) data. We note that if
the Lorentz and $CPT$ symmetries are broken by a Chern-Simons term in the
effective lagrangian, which couples the dual electromagnetic field strength
tensor to an external four-vector, the polarization vectors of propagating CMB
photons are rotated. Using the WMAP data alone, one could put an interesting
constraint on the size of such a term. Combined with the B03 data, we found
that a nonzero rotation angle of the photons is mildly favored: $\Delta \alpha=
-5.3^{+3.9}_{-4.0}$ $^{+4.1}_{-3.5}$deg (1,2 $\sigma$).

\\ ( http://arXiv.org/abs/astro-ph/0601095 , 65kb)

[ljk4-1]

Paper (*cross-listing*): hep-th/0601034

Date: Fri, 6 Jan 2006 04:42:26 GMT (9kb)
Date (revised v2): Sat, 7 Jan 2006 03:16:48 GMT (9kb)

Title: Is Cosmic Parity Violation Responsible for the Anomalies in the WMAP
Data?

Authors: Stephon H.S. Alexander

Comments: 5 pages
\\
This research demonstrates that parity violation in general relativity can
simultaneously explain the observed loss in power and alignment at a preferred
axis ('Axis of Evil')in the low multipole moments of the WMAP data. This
observational possibility also provides an experimental window for an
inflationary leptogenesis mechanism arising from large-scale parity violation.

A velocity dependent potential is induced from gravitational backreaction,
which modifies the primordial scalar angular power spectrum of density
perturbations in the CMB. This modification suppresses power of odd parity
multipoles on large scales which can be associated with the scale of a massive
right-handed neutrino.

\\ ( http://arXiv.org/abs/hep-th/0601034 , 9kb)

[ljk4-1]

Astrophysics, abstract
astro-ph/0601389

From: Harvinder Kaur Jassal [view email]

Date: Wed, 18 Jan 2006 12:50:31 GMT (575kb)

The vanishing phantom menace

Authors: H. K. Jassal, J. S. Bagla (HRI, Allahabad), T. Padmanabhan (IUCAA, Pune)

Comments: 8 pages, 4 figures, MNRAS format

We demonstrate that the recently released high redshift supernova data from the SNLS (SuperNova Legacy Survey) project is in better agreement with CMB observations, unlike the earlier data sets which preferred a different class of models altogether. The SNLS data set favours models similar to the LCDM model. We illustrate that WMAP observations are, by far, the strongest constraint on models with a varying equation of state parameter for the dark energy component in a flat universe. Further, the better quality of observations of temperature anisotropies in the CMB are less susceptible to systematic effects and this makes it a more reliable probe of cosmological parameters and dark energy. This is true even with uncertainties introduced by other undetermined parameters in the problem. However, given the ease with which the supernova observations can be compared with a given cosmological model, theoreticians tend to use only the supernova observations for testing models of dark energy. It is therefore useful to know that the recent SNLS data prefers models similar to those preferred by WMAP, unlike the previous data sets which had a certain amount of discordance with WMAP.

http://arxiv.org/abs/astro-ph/0601389


High Energy Physics - Phenomenology, abstract
hep-ph/0601134

From: Jose Ramon Espinosa [view email]

Date: Tue, 17 Jan 2006 17:55:20 GMT (63kb)

Running Spectral Index as a Probe of Physics at High Scales

Authors: G. Ballesteros, J.A. Casas, J.R. Espinosa

Comments: 33 pages, LaTeX, 5 ps figures

Report-no: IFT-UAM/CSIC-05-51

The WMAP results on the scalar spectral index n and its running with scale, though preliminary, open a very interesting window to physics at very high energies. We address the problem of finding inflaton potentials well motivated by particle physics which can accomodate WMAP data. We make a model independent analysis of a large class of models: those with flat tree-level potential lifted by radiative corrections, which cause the slow rolling of the inflaton and the running of n. This includes typical hybrid inflation models. In the small-coupling regime the predictions for the size and running of n are remarkably neat, e.g. -dn/dln k=(n-1)^2 << 1, and n does not cross n=1, contrary to WMAP indications. On the other hand, n can run significantly if the couplings are stronger but at the price of having a small number of e-folds, Ne. We also examine the effect of mass thresholds crossed during inflation. Finally, we show that the presence of non-renormalizable operators for the inflaton, suppressed by a mass scale above the inflationary range, is able to give both dn/dln k ~ O(-0.05) and Ne ~ 50.

http://arxiv.org/abs/hep-ph/0601134

[ljk4-1]

Paper: astro-ph/0601427
Date: Thu, 19 Jan 2006 16:26:07 GMT (220kb)

Title: The non-Gaussian Cold Spot in WMAP: significance, morphology and
foreground contribution

Authors: M. Cruz, M. Tucci, E. Martinez-Gonzalez and P. Vielva

Comments: 11 pages, 8 figures, submitted to MNRAS
\\
The non--Gaussian cold spot in the 1-year WMAP data, described in Vielva et
al. and Cruz et al., is analysed in detail in the present paper. First of all,
we perform a more rigorous calculation of the significance of the non-zero
kurtosis detected in WMAP maps by Vielva et al. in wavelet space, mainly
generated by the Spot. We confirm the robustness of that detection, since the
probability of obtaining this deviation by chance is 0.69%. Afterwards, the
morphology of the Spot is studied by applying Spherical Mexican Hat Wavelets
with different ellipticities. The shape of the Spot is found to be almost
circular. Finally, we discuss if the observed non-Gaussianity in wavelet space
can arise from bad subtracted foreground residues in the WMAP maps. We show
that the flat frequency dependence of the Spot cannot be explained by a thermal
Sunyaev-Zeldovich effect. Based on our present knowledge of Galactic foreground
emissions, we conclude that the significance of our detection is not affected
by Galactic residues in the region of the Spot. Considering different Galactic
foreground estimates, we always obtain an upper tail probability below 1% for
the size of the Spot compared to the simulations.

\\ ( http://arXiv.org/abs/astro-ph/0601427 , 220kb)

[ljk4-1]

Astrophysics, abstract
astro-ph/0602023

From: Laura Cayon [view email]

Date: Wed, 1 Feb 2006 18:46:47 GMT (280kb)

No Higher Criticism of the Bianchi Corrected WMAP Data

Authors: L. Cayon (1), A.J. Banday (2), T. Jaffe (2), H.K. Eriksen (3,4,5), F.K. Hansen (3,4), K.M. Gorski (5), J. Jin (6) ((1)Department of Physics. Purdue University,(2)Max-Planck-Institut fur Astrophysik, Garching,(3)Institute of Theoretical Astrophysics, University of Oslo,(4)Centre of Mathematics for Applications, University of Oslo,(5)JPL,(6)Department of Statistics. Purdue University)

Comments: submitted to MNRAS

Motivated by the success of the Bianchi VII_h model in addressing many of the anomalies observed in the WMAP data (Jaffe et al.), we present calculations in real and in wavelet space of the Higher Criticism statistic of the Bianchi corrected Wilkinson Microwave Anisotropy Probe (WMAP) first year data. At the wavelet scale of 5 degrees the Higher Criticism of the WMAP map drops from a value above the 99% c.l. to a value below the 68% c.l. when corrected by the Bianchi template. An important property of the Higher Criticism statistic is its ability to locate the pixels that account for the deviation from Gaussianity. The analysis of the uncorrected WMAP data pointed to a cold spot in the southern hemisphere centered at (l,~ (209, -57). The Higher Criticism of the Bianchi corrected map indicates that this spot remains prominent, albeit at a level completely consistent with Gaussian statistics. Consequently, it is debatable how much emphasis should be placed on this residual feature, but we consider the effect of modestly increasing the scaling of the template. A factor of only 1.2 renders the spot indistinguishable from the background level, with no noticeable impact on the results published in Jaffe et al. for the low-l anomalies, large-scale power asymmetry or wavelet kurtosis. A trivial interpretation would be that the Bianchi template may require a small enhancement of power on scales corresponding to the wavelet scale of 5 degrees.

http://arxiv.org/abs/astro-ph/0602023

[antoniseb]

Thursday March 16th, noon EST.
Talks and papers at NASA on the second release.