No Arabic abstract
Quasars provide our farthest-reaching view of the Universe. The Sloan Survey now contains over 100,000 quasar candidates. A careful look at the angular distribution of quasar magnitudes shows a surprising intensity enhancement with a bulls eye pattern toward (alpha,delta) ~ (195{deg}, 0{deg}) for all wavelengths from UV through infrared. The angular pattern and size of the enhancement is very similar for all wavelengths, which is inconsistent with a Doppler shift due to a large peculiar velocity toward that direction. The shift is also too large to explain as a systematic error in the quasar magnitudes. The general features of the anomaly can be explained by the gravitational lensing of a massive bubble with Mlens ~ 10^21 Modot, a lens radius ~350 Mpc, and with the lens subtending an angle of pm15{deg} on the sky. It is remarkable that the presence of such a massive bubble universe can explain not only the anomalies in the angular distribution of quasar intensities, but also anomalies in the distribution of luminous red galaxies, anomalies in the CMB, and bulk flow discrepancies, all of which appear in roughly the same direction.
This is a very informal report that gives further details on the evidence for a bubble universe based on an anomaly in the angular distribution of quasar magnitudes that was presented in a short paper in arXiv:1202.4433. This report addresses some concerns of two reviewers. It is meant to be read in conjunction with 1202.4433. There is very little overlap between the two articles. This extended discussion is, by necessity, somewhat more technical in nature. I am grateful for the reviewers comments that forced me to understand these issues more thoroughly.
Quasars provide our farthest-reaching view of the Universe. The Sloan Survey now contains over 100,000 quasar candidates. A careful look at the angular distribution of quasar spectra shows a surprising bullseye pattern on the sky toward (RA, Dec) ~ (190{deg}, 0{deg}) for all wavelengths from UV through infrared. The angular distribution of the shift in the UV suggests a large peculiar velocity vp toward that direction. However, the size of the shift would indicate a vp ~0.2 c, which is two orders of magnitude larger than measures of our peculiar velocity from nearby galaxies and cosmic microwave background (CMB) measurements. The angular pattern and size of the shift is very similar for all wavelengths, which is inconsistent with a Doppler shift. The shift is also too large to explain as a systematic error in the quasar magnitudes. The anomaly appears to be a very large hotspot in the Universe. Its direction is close to that of the reported anomalies in the CMB, the so-called axis of evil. The angular pattern of the shift and its redshift dependence are consistent with the existence of an expanding bubble universe in that direction, which could also explain the CMB anomalies.
The measurement of present-day temperature of the Cosmic Microwave Background (CMB), $T_0 = 2.72548 pm 0.00057$ K (1$sigma$), made by the Far-InfraRed Absolute Spectrophotometer (FIRAS), is one of the most precise measurements ever made in Cosmology. On the other hand, estimates of the Hubble Constant, $H_0$, obtained from measurements of the CMB temperature fluctuations assuming the standard $Lambda$CDM model exhibit a large ($4.1sigma$) tension when compared with low-redshift, model-independent observations. Recently, some authors argued that a slightly change in $T_0$ could alleviate or solve the $H_0$-tension problem. Here, we investigate evidence for a hotter or colder universe by performing an independent analysis from currently available temperature-redshift $T(z)$ measurements. Our analysis (parametric and non-parametric) shows a good agreement with the FIRAS measurement and a discrepancy of $gtrsim 1.9sigma$ from the $T_0$ values required to solve the $H_0$ tension. This result reinforces the idea that a solution of the $H_0$-tension problem in fact requires either a better understanding of the systematic errors on the $H_0$ measurements or new physics.
We present a regular cubic lattice solution to Einstein field equations that is exact at second order in a small parameter. We show that this solution is kinematically equivalent to the Friedmann-Lema^itre-Robertson-Walker (FLRW) solution with the same averaged energy density. This allows us to discuss the fitting problem in that framework: are observables along the past lightcone of observers equivalent to those in the analogue FLRW model obtained by smoothing spatially the distribution of matter? We find a criterion on the compacity of the objects that must be satisfied in order for the answer to this question to be positive and given by perturbative arguments. If this criterion is not met, the answer to this question must be addressed fully non perturbatively along the past lightcone, even though the spacetime geometry can be described perturbatively.
A wavelike solution for the non-relativistic universal dark matter (wave-DM) is rapidly gaining interest, following distinctive predictions of pioneering simulations of cosmic structure as an interference pattern of coherently oscillating bosons. A prominent solitonic standing wave is predicted at the center of every galaxy, representing the ground state, that has been identified with the wide, kpc scale dark cores of common dwarf-spheroidal galaxies, providing a boson mass of, $simeq 10^{-22}$ eV. A denser soliton is predicted for Milky Way sized galaxies where momentum is higher, so the de Broglie scale of the soliton is smaller, $simeq 100$ pc, of mass $simeq 10^9 M_odot$. Here we show the central motion of bulge stars in the Milky Way implies the presence of such a dark core, where the velocity dispersion rises inversely with radius to a maximum of $simeq 130$ km/s, corresponding to an excess central mass of $simeq 1.5times 10^9 M_odot$ within $simeq 100$ pc, favouring a boson mass of $simeq 10^{-22}$ eV. This quantitative agreement with such a unique and distinctive prediction is therefore strong evidence for a light bosonic solution to the long standing Dark Matter puzzle, such as the axions generic in String Theory.