No Arabic abstract
Cyclostationary processes are those signals whose have vary almost periodically in statistics. It can give rise to random data whose statistical characteristics vary periodically with time although these processes not periodic functions of time. Intermittent pulsar is a special type in pulsar astronomy which have period but not a continuum. The Rotating RAdio TransientS (RRATs) represent a previously unknown population of bursting neutron stars. Cyclical period changes of variables star also can be thought as cyclostationary which are several classes of close binary systems. Quasi-Periodic Oscillations (QPOs) refer to the way the X-ray light from an astronomical object flickers about certain frequencies in high-energy (X-ray) astronomy. I think that all above phenomenon is cyclostationary process. I describe the signal processing of cyclostationary, then discussed that the relation between it and intermittent pulsar, RRATs, cyclical period changes of variables star and QPOs, and give the perspective of finding the cyclostationary source in the transient universe.
We perform a deductive study of accelerating Universe and focus on the importance of variable time-dependent $Lambda$ in the Einsteins field equations under the phenomenological assumption, $Lambda =alpha H^2$ for the full physical range of $alpha$. The relevance of variable $Lambda$ with regard to various key issues like dark matter, dark energy, geometry of the field, age of the Universe, deceleration parameter and barotropic equation of state has been trivially addressed. The deceleration parameter and the barotropic equation of state parameter obey a straight line relationship for a flat Universe described by Friedmann and Raychaudhuri equations. Both the parameters are found identical for $alpha = 1$.
This paper presents a compelling argument for the physical light speed in the Friedman-Lemaitre-Robertson-Walker (FLRW) universe to vary with the cosmic time coordinate t of FLRW. It must be variable when the radial comoving differential coordinates of FLRW is interpreted as physical and therefore transformable by a Lorentz transform locally to differentials of stationary physical coordinates. Because the FLRW differential radial distance has a time varying coefficient a(t), integration of the transformed differentials to obtain stationary coordinates for a short radial distance requires the light speed c(t) to be proportional to the square root of da/dt. Since we assume homogeneity of space, this derived c(t) is the physical light speed on all points of the FLRW universe. This impacts the interpretation of all astronomical observations of distant phenomena that are sensitive to light speed. A world transform from FLRW that has a Minkowski metric close to the origin is shown to have a physical radius out to all points of the visible universe. In order to obtain numerical values for c(t), the general relativity (GR) field equation is extended by using a variable gravitational constant and rest mass that keeps constant the gravitational and particle rest energies. This also keeps constant the proportionality constant between the GR tensors of the field equation and conserves the rest stress-energy tensor of the ideal fluid used in the FLRW GR field equation. In the same way all of special and general relativity is extended to include a variable light speed.
From the observed results of the space distribution of quasars we deduced that neutrino mass is about 10^(-1) eV. The fourth stable elementary particle (delta particle) with mass about 10^(0) eV can help explain the energy resource mechanism in quasars, cosmic ultra-high energy particles, as well as the flatness of spiral galaxy rotation curves. The blue bump and IR bump in the quasar irradiation spectra, as well as the peaks of EBL (Extra-galactic Background Light) around 10^(0) eV and 10^(-1) eV, are related to the annihilation of delta particle with anti-delta particle and neutrino with anti-neutrino respectively. This enlightens us to explore the reason for missing solar neutrinos and the unlimited energy resource in a new manner. For delta-particle search it is related to Dual SM or Two-fold SM; the relationship between space electron spectrum (>10^(0)Tev) and cosmic ray spectrum (knee and ankle) at high energy region; and the characteristics of spherical universe. Appendix is the theory part, which related to mass tree, inflation, BSM, finite universe.
The Hubble law, determined from the distance modulii and redshifts of galaxies, for the past 80 years, has been used as strong evidence for an expanding universe. This claim is reviewed in light of the claimed lack of necessary evidence for time dilation in quasar and gamma-ray burst luminosity variations and other lines of evidence. It is concluded that the observations could be used to describe either a static universe (where the Hubble law results from some as-yet-unknown mechanism) or an expanding universe described by the standard Lambda cold dark matter model. In the latter case, size evolution of galaxies is necessary for agreement with observations. Yet the simple non-expanding Euclidean universe fits most data with the least number of assumptions. From this review it is apparent that there are still many unanswered questions in cosmology and the title question of this paper is still far from being answered.
Based on the equivalence of the two different types of measurement protocols and the asymmetry between the Schrodinger and Heisenberg pictures, it has been previously proposed that negative sea fills the universe as a nondeterministic computation - a time-reversal process of the irreversible computations presented since the big bang. The goal of this paper is to extend the proposed subjective universe model, i.e., the universe as a quantum measurement: Motivated by the relationship between quantum theory and classical probability theory with continuity, it is argued that the frame of reference of the observer may be identified with classical probability theory where its choice, along with big bang singularity, should correspond to the quantum observable. That is, the physical version of singularity resolution corresponds to the case, where big bang singularity is equivalent to the continuity of the negative sea, or aether, filling the universe as a frame of reference of the observer. Moreover, based on the holographic principle, we identify the choice of the observer with the degrees of freedom proportional to the Planck area on the horizon. We also discuss that the continuity or infinity present in every formal language of choice acceptable in nondeterministic computation may be associated with the universal grammar proposed by Chomsky in linguistics.