New evidence for lack of CMB power on large scales

A digitalized temperature map is recovered from the first light sky survey image published by the Planck team, from which an angular power spectrum is derived. The amplitudes of the low multipoles measured from the preliminary Planck power spectrum are significantly lower than that reported by the WMAP team. Possible systematical effects are far from enough to explain the observed low-l differences.Comment: 9 pages, 3 figure

1/Nc1/N_c Rotational Corrections to gAg_A and Isovector Magnetic Moment of the Nucleon

The $1/N_c$ rotational corrections to the axial vector constant and the isovector magnetic moment of the nucleon are studied in the Nambu -- Jona-Lasinio model. We follow a semiclassical quantization procedure in terms of path integrals in which we can include perturbatively corrections in powers of angular velocity $\Omega \sim \frac 1{N_c}$. We find non-zero $1/N_c$ order corrections from both the valence and the Dirac sea quarks. These corrections are large enough to resolve the long-standing problem of a strong underestimation of both $g_A$ and $\mu^{IV}$ in the leading order. The axial constant $g_A$ is well reproduced, whereas the isovector magnetic moment $\mu^{IV}$ is still underestimated by 25 \%.Comment: (Revtex), 10 pages (3 figures available on request), report RUB-TPII-53/9

A Single Antibody based ELISA for the N-terminal sequence of BAG-75, a New Biomarker for Bone Formation [abstract]

Biomedical Tissue Engineering, Biomaterials, & Medical Devices Poster SessionBone acidic glycoprotein-75 (BAG-75) is a secreted product of osteoblastic cells localized predominantly to areas of new bone formation. We have identified the N-terminal sequence of BAG-75 as LPVARYQNTEEEE and shown that anti-peptide antibodies against residues #3-13 only recognize the 75 kDa precursor and apparent 50 kDa fragment in serum and in osteoblastic cultures. Formation of the 50 kDa fragment is blocked by AEBSF, a serine protease inhibitor which we also showed blocks mineralization in osteoblastic cultures. Measurement of BAG-75 and its fragment concentration in serum represents a new method to estimate the rate of new bone formation in vivo. Our purpose was to establish an anti-VARYQNTEEEE peptide antibody based ELISA test to measure cross-reactive proteins released from bone into blood. Western blotting was performed using young rat serum from different ages, rats subjected to ovariectomy (OVX) or sham surgery, and normal human serum. Immunoreactive 50 kDa fragment peaked at 18 days after birth which parallels bone formation. Ovariectomized rats displayed a peak of 50 kDa immunoreactivty at 21 days after surgery which corresponds to a spike in bone formation in this model (~2.5-fold above controls). Comparable assays for osteocalcin showed only a 39% increase. Also, human serum contains a 50 kDa protein which cross-reacts with anti-VARYQNTEEEE antibodies. We then established a competitive 96-well ELISA using anti-peptide antibody and new sera at 21 days from ovariectomized or sham rats, a model for stimulated bone formation. VARYQNTEEEE peptide conjugated to keyhole limpet hemocyanin (KLH) was used as the bound antigen. KLH-peptide amount, primary antibody concentration, secondary antibody concentration, and blocking agent were optimized in a series of experiments. Optimal conditions were determined to be 2 µg input KLH-peptide per well, 1/5,000 dilution of primary anti-VARYQNTEEEE antibody, 1/10,000 dilution of secondary antibody, and gelatin as a blocking agent. Sera from OVX rats and sham-operated controls were compared to the standard curve (r = 0.9923) created with free KLH-peptide as competitor to determine the equivalent amount of KLH-peptide present. OVX sera (n=3) contained an average 2.6 x 10-4 (+/- 1.4 x 10-4) µg peptide equivalent versus 1.05 x 10-4 (+/- 0.68 x 10-4) µg for sham sera (n=3). The difference was not significant (t-test, p=0.157), however, doubling the sample size is predicted to yield significance. Conclusions: A. Cross-reactive 75 kDa and 50 kDa proteins are present in human and rat serum and increase in concentration when bone formation is stimulated. B. A new, single antibody based ELISA assay was established to quantitate antigen released from bone into blood. C. In contrast to other commercial bone formation assays (collagen peptides and osteocalcin), the size of cross-reactive protein (>50 kDa) should preclude kidney filtration and facilitate measurement. D. This serum biomarker undergoes a 2-3 fold average increase within 3 weeks after simulation of bone. This test may be useful to monitor the early response to stimulatory therapy in osteoporosis patients or to repressive glucocorticoid therapy in sarcoidosis patients. Currently, a 1% change in bone mineral density requires 12-18 months to detect by x-ray methods

An optimally concentrated Gabor transform for localized time-frequency components

Gabor analysis is one of the most common instances of time-frequency signal analysis. Choosing a suitable window for the Gabor transform of a signal is often a challenge for practical applications, in particular in audio signal processing. Many time-frequency (TF) patterns of different shapes may be present in a signal and they can not all be sparsely represented in the same spectrogram. We propose several algorithms, which provide optimal windows for a user-selected TF pattern with respect to different concentration criteria. We base our optimization algorithm on $l^p$-norms as measure of TF spreading. For a given number of sampling points in the TF plane we also propose optimal lattices to be used with the obtained windows. We illustrate the potentiality of the method on selected numerical examples

Non-Gaussian CMBR angular power spectra

In this paper we show how the prediction of CMBR angular power spectra $C_l$ in non-Gaussian theories is affected by a cosmic covariance problem, that is $(C_l,C_{l'})$ correlations impart features on any observed $C_l$ spectrum which are absent from the average $C^l$ spectrum. Therefore the average spectrum is rendered a bad observational prediction, and two new prediction strategies, better adjusted to these theories, are proposed. In one we search for hidden random indices conditional to which the theory is released from the correlations. Contact with experiment can then be made in the form of the conditional power spectra plus the random index distribution. In another approach we apply to the problem a principal component analysis. We discuss the effect of correlations on the predictivity of non-Gaussian theories. We finish by showing how correlations may be crucial in delineating the borderline between predictions made by non-Gaussian and Gaussian theories. In fact, in some particular theories, correlations may act as powerful non-Gaussianity indicators

p-Wave holographic superconductors with Weyl corrections

We study the (3+1) dimensional p-wave holographic superconductors with Weyl corrections both numerically and analytically. We describe numerically the behavior of critical temperature $T_{c}$ with respect to charge density $\rho$ in a limited range of Weyl coupling parameter $\gamma$ and we find in general the condensation becomes harder with the increase of parameter $\gamma$. In strong coupling limit of Yang-Mills theory, we show that the minimum value of $T_{c}$ obtained from analytical approach is in good agreement with the numerical results, and finally show how we got remarkably a similar result in the critical exponent 1/2 of the chemical potential $\mu$ and the order parameter$$ with the numerical curves of superconductors.Comment: 7 pages, 1 figure, 1 table. One refrence added, presentations improve

Multipole vector anomalies in the first-year WMAP data: a cut-sky analysis

We apply the recently defined multipole vector framework to the frequency-specific first-year WMAP sky maps, estimating the low-l multipole coefficients from the high-latitude sky by means of a power equalization filter. While most previous analyses of this type have considered only heavily processed (and foreground-contaminated) full-sky maps, the present approach allows for greater control of residual foregrounds, and therefore potentially also for cosmologically important conclusions. The low-l spherical harmonics coefficients and corresponding multipole vectors are tabulated for easy reference. Using this formalism, we re-assess a set of earlier claims of both cosmological and non-cosmological low-l correlations based on multipole vectors. First, we show that the apparent l=3 and 8 correlation claimed by Copi et al. (2004) is present only in the heavily processed map produced by Tegmark et al. (2003), and must therefore be considered an artifact of that map. Second, the well-known quadrupole-octopole correlation is confirmed at the 99% significance level, and shown to be robust with respect to frequency and sky cut. Previous claims are thus supported by our analysis. Finally, the low-l alignment with respect to the ecliptic claimed by Schwarz et al. (2004) is nominally confirmed in this analysis, but also shown to be very dependent on severe a-posteriori choices. Indeed, we show that given the peculiar quadrupole-octopole arrangement, finding such a strong alignment with the ecliptic is not unusual.Comment: 13 pages, 2 figures; corrected typos; added reference. Accepted for publication in Ap

Footprints of Statistical Anisotropies

We propose and develop a formalism to describe and constrain statistically anisotropic primordial perturbations. Starting from a decomposition of the primordial power spectrum in spherical harmonics, we find how the temperature fluctuations observed in the CMB sky are directly related to the coefficients in this harmonic expansion. Although the angular power spectrum does not discriminate between statistically isotropic and anisotropic perturbations, it is possible to define analogous quadratic estimators that are direct measures of statistical anisotropy. As a simple illustration of our formalism we test for the existence of a preferred direction in the primordial perturbations using full-sky CMB maps. We do not find significant evidence supporting the existence of a dipole component in the primordial spectrum.Comment: 26 pages, 5 double figures. Uses RevTeX

A re-analysis of the three-year WMAP temperature power spectrum and likelihood

We analyze the three-year WMAP temperature anisotropy data seeking to confirm the power spectrum and likelihoods published by the WMAP team. We apply five independent implementations of four algorithms to the power spectrum estimation and two implementations to the parameter estimation. Our single most important result is that we broadly confirm the WMAP power spectrum and analysis. Still, we do find two small but potentially important discrepancies: On large angular scales there is a small power excess in the WMAP spectrum (5-10% at l<~30) primarily due to likelihood approximation issues between 13 <= l <~30. On small angular scales there is a systematic difference between the V- and W-band spectra (few percent at l>~300). Recently, the latter discrepancy was explained by Huffenberger et al. (2006) in terms of over-subtraction of unresolved point sources. As far as the low-l bias is concerned, most parameters are affected by a few tenths of a sigma. The most important effect is seen in n_s. For the combination of WMAP, Acbar and BOOMERanG, the significance of n_s =/ 1 drops from ~2.7 sigma to ~2.3 sigma when correcting for this bias. We propose a few simple improvements to the low-l WMAP likelihood code, and introduce two important extensions to the Gibbs sampling method that allows for proper sampling of the low signal-to-noise regime. Finally, we make the products from the Gibbs sampling analysis publically available, thereby providing a fast and simple route to the exact likelihood without the need of expensive matrix inversions.Comment: 14 pages, 7 figures. Accepted for publication in ApJ. Numerical results unchanged, but interpretation sharpened: Likelihood approximation issues at l=13-30 far more important than potential foreground issues at l <= 12. Gibbs products (spectrum and sky samples, and "easy-to-use" likelihood module) available from http://www.astro.uio.no/~hke/ under "Research