Cosmological Lambda Research Articles

Wrong Definition and Wrong Implications of Cosmic Red Shift (Correction and Possible Solutions)

Since 1912, cosmologists strongly believe in the currently accepted definition of cosmic red shift as - ratio of increase in wavelength to the laboratory wavelength of photon. We would like to emphasize the point that, this definition is absolutely wrong with reference to photon energy. Clearly speaking, true cosmic red shift must be defined as the ratio of loss in energy of photon to the energy of photon at laboratory. In terms of wavelength, photon red shift must be defined as the ratio of increase in wavelength to the observed wavelength of photon. We have published this definition in our recent publications and sincerely appeal the science community and cosmologists to review the basics of Lambda cosmology, cosmic acceleration and dark energy in an unbiased approach. Regarding Tolman Surface Brightness test, we sincerely appeal the cosmologists to review and reanalyze the observations and calculations as per the corrected cosmic redshift definition with reference to cosmic expansion and cosmic rotation. Here we would like to emphasize the point that, (1+z) should be replaced by (1+znew). Upper limit of (1+znew) is 2 and upper limit of (1+znew)4 is 16

Massive particle pair production and oscillation in Friedman Universe: reheating energy and entropy, and cold dark matter

Suppose that the early Universe starts with a cosmological Lambda -term (dark energy) originating from quantum spacetime at the Planck scale. Dark energy drives inflation and reheating by reducing its value for massive particle–antiparticle pairs production and oscillation, resulting in a holographic and massive pair plasma state. The back-and-forth reaction of dark energy and massive pairs slows inflation to its end and starts reheating by rapidly producing stable and unstable pairs. We introduce the Boltzmann-type rate equation describing the back-and-forth reaction. It forms a close set with Friedman equations and reheating equations for unstable pairs decay to relativistic particles. The numerical solutions show preheating, massive pairs dominated and genuine reheating episodes. We obtain the reheating temperature and entropy in terms of the tensor-to-scalar ratio 0< r < 0.047 consistently with observations. Stable massive pairs represent cold dark matter particles and weakly interact with dark energy. The resultant cold dark matter abundance Omega _csim 10^{-1} is about a constant in time.

Mass and Energy Densities of the Cosmos

Fundamental principles of classical (Newtonian) physics are employed to probe the cosmological lambda &amp;Lambda;; it yields the values &amp;rho;vac = 2.61 x 10-39 g cm-3 and &amp;Lambda; = 4.87 x 10-66 cm-2. It is revealed that &amp;Lambda; is a fundamental physical constant defined by vacuum density-light speed &amp;rho;vacc2 correlation. However, the constant accelerates along the groups and periods of a universal spatial periodicity equivalent to the chemical periodicity. Previous results are cited to show that chemical elements are quantum harmonic (periodic) oscillators QHOs and their waveform oscillations exclusively define the vacuum field. The cosmological periodic unit CPU is introduced, it relies on the cosmological principle to argue that a relative physical quantity evaluated for the QHO applies to constituents of corresponding cosmological spatial quanta. Compelling evidences, backed with relevant data and quantitative expressions, are presented to argue that: there was never a big bang, it is a Linde-universe sans &amp;ldquo;chaotic&amp;rdquo;; nature posts no singularity; mass does not curve spacetime, neither does metric space curvature trace directly to gravitation nor particle creation, gravity is classical, not quantum; reality is quadri-phasic not mono-phasic with a clear distinction between the atomic waveform defined with absolute atomic mass and condensed matter defined with relative atomic mass; every chemical element exists in three particle-generations thus, dark matter is invisible form (conjugate) of the visible element, its waveform manifests dark energy, it is not implicated in metric space expansion; Planck scale does not exist, radioactivity constrains fundamental length to atomic radius of the heaviest element.

Dynamical analysis and cosmological viability of varying G and Lambda cosmology

The cosmological viability of varying Gleft( tright) and Lambda left( tright) cosmology is discussed by determining the cosmological eras provided by the theory. Such a study is performed with the determination of the critical points while stability analysis is performed. The application of renormalization group in the ADM formalism of general relativity provides a modified second-order theory of gravity where varying Gleft( tright) plays the role of a minimally coupled field, different from that of scalar–tensor theories, while Lambda left( tright) =Lambda left( Gleft( tright) right) is a potential term. We find that the theory provides two de Sitter phases and a tracking solution. In the presence of matter source, two new critical points are introduced, where the matter source contributes to the universe. One of those points describes the Lambda CDM cosmology and in order for the solution at the point to be cosmologically viable, it has to be unstable. Moreover, the second point, where matter exists, describes a universe where the dark energy parameter for the equation of state has a different value from that of the cosmological constant.

Using Noether symmetries to specify f(R) gravity

A detailed study of the modified gravity, f(R) models is performed, using the fact that the Noether point symmetries of these models are geometric symmetries of the mini su-perspace of the theory. It is shown that the requirement that the field equations admit Noether point symmetries selects definite models in a self-consistent way. As an application in Cosmology we consider the Friedman -Robertson-Walker spacetime and show that the only cosmological model which is integrable via Noether point symmetries is the (Rb − 2Λ)c model, which generalizes the Lambda Cosmology. Furthermore using the corresponding Noether integrals we compute the analytic form of the main cosmological functions.

Measuring the Matter Density Using Baryon Oscillations in the SDSS

We measure the cosmological matter density by observing the positions of baryon acoustic oscillations in the clustering of galaxies in the Sloan Digital Sky Survey (SDSS). We jointly analyse the main galaxies and LRGs in the SDSS DR5 sample, using over half a million galaxies in total. The oscillations are detected with 99.74% confidence (3.0sigma assuming Gaussianity) compared to a smooth power spectrum. When combined with the observed scale of the peaks within the CMB, we find a best-fit value of Omega_m=0.256+0.029-0.024 (68% confidence interval), for a flat Lambda cosmology when marginalising over the Hubble parameter and the baryon density. This value of the matter density is derived from the locations of the baryon oscillations in the galaxy power spectrum and in the CMB, and does not include any information from the overall shape of the power spectra. This is an extremely clean cosmological measurement as the physics of the baryon acoustic oscillation production is well understood, and the positions of the oscillations are expected to be independent of systematics such as galaxy bias.

Multiple lambda cosmology: Dark fluid with time-dependent equation of state as classical analog of cosmological landscape

We discuss FRW universe with time-dependent EoS dark fluid which leads to multiple de Sitter space. This model (as well as its scalar-tensor version) may be considered as some classical analog of cosmological landscape. The universe expansion history may look as transitions between different de Sitter eras what suggests the interesting solution for cosmological constant problem. For specific time-dependent EoS dark fluid the possibility of transitions between universe regions with positive and negative cosmological constant is also established.

The 2dF QSO Redshift Survey -- XI. The QSO power spectrum

We present a power spectrum analysis of the final 2dF QSO Redshift Survey catalogue containing 22652 QSOs. Utilising the huge volume probed by the QSOs, we can accurately measure power out to scales of ~500Mpc and derive new constraints, at z~1.4, on the matter and baryonic contents of the Universe. Importantly, these new cosmological constraints are derived at an intermediate epoch between the CMB observations at z~1000, and local (z~0) studies of large-scale structure; the average QSO redshift corresponds to a look-back time of approximately two-thirds of the age of the Universe. We find that the amplitude of clustering of the QSOs at z~1.4 is similar to that of present day galaxies. The power spectra of the QSOs at high and low redshift are compared and we find little evidence for any evolution in the amplitude. Assuming a lambda cosmology to derive the comoving distances, r(z), to the QSOs, the power spectrum derived can be well described by a model with shape parameter Gamma=0.13+-0.02. If an Einstein-de Sitter model r(z) is instead assumed, a slightly higher value of Gamma=0.16+-0.03 is obtained. A comparison with the Hubble Volume LCDM simulation shows very good agreement over the whole range of scales considered. A standard (Omega_m=1) CDM model, however, predicts a much higher value of Gamma than is observed, and it is difficult to reconcile such a model with these data. We fit CDM model power spectra (assuming scale-invariant initial fluctuations), convolved with the survey window function, and corrected for redshift space distortions, and find that models with baryon oscillations are slightly preferred, with the baryon fraction Omega_b/Omega_m=0.18+-0.10. The overall shape of the power spectrum provides a strong constraint on Omega_m*h (where h is the Hubble parameter), with Omega_m*h=0.19+-0.05.

Mass and Light in the Universe

We present a weak lensing and photometric study of six 05 × 05 fields observed at the Canada-France-Hawaii Telescope using the UH8K CCD mosaic camera. The fields were observed for a total of 2 hr each in I and V, resulting in catalogs containing ~20,000 galaxies per passband per field. We use V-I color and I magnitude to select bright early-type galaxies at redshifts 0.1 < z < 0.9. We measure the gravitational shear from faint galaxies in the range 21 < mI < 25 from a composite catalog and find a strong correlation with that predicted from the early types if they trace the mass with M/LB 300 ± 75 h M☉/L☉ for a flat (Ωm0 = 0.3,Ωλ0 = 0.7) lambda cosmology and M/LB 400 ± 100 h M☉/L☉ for Einstein-de Sitter. We make two-dimensional reconstructions of the mass surface density. Cross-correlation of the measured mass surface density with that predicted from the early-type galaxy distribution shows a strong peak at zero lag (significant at the 5.2 σ level). We azimuthally average the cross-correlation and autocorrelation functions. We conclude that the profiles are consistent with early-type galaxies tracing mass on scales of ≥45'' (≥200 h-1 kpc at z = 0.5). We subdivide our bright early-type galaxies by redshift and obtain similar conclusions. These M/LB ratios imply Ωm0 0.10 ± 0.02 (Ωm0 0.13 ± 0.03 for Einstein-de Sitter) of closure density.

Quasar populations in a cosmological constant-dominated flat universe

Most physical properties derived for quasars, as single entities or as a population, depend upon the cosmology assumed. In this paper, we calculate the quasar luminosity function and some related quantities for a flat universe dominated by a cosmological constant Lambda (Lambda = 0.9, Omega = 0.1) and compare them with those deduced for a flat universe with zero cosmological constant (Lambda = 0, Omega = 1). We use the ATT quasar survey data (Boyle et al. 1990) as input in both cases. The data are fitted well by a pure luminosity evolution model for both the cosmologies but with different evolutionary parameters. From the luminosity function, we predict (extrapolate) a greater number of quasars at faint apparent magnitudes (twice the number at B = 24, z is less than 2.2) for the Lambda-dominated universe. This population of faint quasars at high redshift would result in a higher incidence of gravitational lensing. The total luminosity of the quasar population and the total mass tied up in black hole remnants of quasars is not sensitive to the cosmology. However, for a Lambda cosmology, this mass is tied up in fewer but more massive black holes.