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We generalize the universal effective quantum number introduced earlier for centrally symmetric problems. The proposed number determines the semiclassical quantization condition for axially symmetric potentials.
This paper reviews the well-known fact that nilpotent Hermitian operators on physical state spaces are zero, thereby indicating that the supersymmetries and "Grassmann numbers" are also zero on these spaces. Next, a positive definite inner product of a Grassmann algebra is demonstrated, constructed using a Hodge dual operator which is similar to that of differential forms. From this example, it is shown that the Hermitian conjugates of the basis do not anticommute with the basis and, therefore, the property that "Grassmann numbers" commute with "bosonic quantities" and anticommute with "fermionic quantities", must be revised. Hence, the fundamental principles of supersymmetry must be called into question.
In this work we investigate the background dynamics when dark energy is coupled to dark matter with a suitable interaction in the universe described by Einstein-Aether gravity. Dark energy in the form of Modified Chaplygin gas is considered. A suitable interaction between dark energy and dark matter is considered in order to at least alleviate (if not solve) the cosmic coincidence problem. The dynamical system of equations is solved numerically and a stable scaling solution is obtained. A significant attempt towards the solution of the cosmic coincidence problem is taken. The statefinder parameters are also calculated to classify the dark energy models. Graphs and phase diagrams are drawn to study the variations of these parameters. It is also seen that the background dynamics of modified Chaplygin gas in Einstein-Aether gravity is completely consistent with the notion of an accelerated expansion in the late universe. Finally, it has been shown that the universe follows the power law form of expansion around the critical point.
Fractional calculus is an effective tool in incorporating the effects of non-locality and memory into physical models. In this regard, successful applications exist rang- ing from signal processing to anomalous diffusion and quantum mechanics. In this paper we investigate the fractional versions of the stellar structure equations for non radiating spherical objects. Using incompressible fluids as a comparison, we develop models for constant density Newtonian objects with fractional mass distributions or stress conditions. To better understand the fractional effects, we discuss effective values for the density, gravitational field and equation of state. The fractional ob- jects are smaller and less massive than integer models. The fractional parameters are related to a polytropic index for the models considered.
The BICEP2 collaboration reported recently a B-mode polarization of the cosmic microwave background (CMB) radiation inconsistent with the null hypothesis at a significance of > 5 σ. This result has been often interpreted as a signature of primordial gravitational waves from cosmic inflation, even if actually polarized dust emission may be at the origin of such a signal. Even assuming that part of this CMB B-mode polarization really corresponds to the early Universe dynamics, its interpretation in terms of inflation and primordial gravitational waves is not the only possible one. Alternative cosmologies such as pre-Big Bang patterns and the spinorial space-time (SST) we introduced in 1996-97 can naturally account for such CMB B-modes. In particular, the SST automatically generates a privileged space direction (PSD) whose existence may have been confirmed by Planck data. If such a PSD exists, it seems normal to infer that vector perturbations have been present in the early Universe leading to CMB B-modes in suitable cosmological patterns. Inflation would not be required to explain the BICEP2 result assuming it really contains a primordial signal. More generally, pre-Big Bang cosmologies can also generate gravitational waves in the early Universe without any need for cosmic inflation. We further discuss here possible alternatives to the inflationary interpretation of a primordial B-mode polarization of cosmic microwave background radiation.
This paper examines the processes involved in attempting to capture the subtlest aspects of nature by the scientific method and argues on this basis that nature is fundamentally elusive and may resist grasping by the methods of science. If we wish to come to terms with this resistance, then a shift in the direction of taking direct experience into account may be necessary for science's future complete development.
The Hybrid Composite Beam (HCB) system is an innovative structural technology that has been recently used in bridge construction within the U.S. transportation network. In this system, the superstructure consists of a conventional reinforced concrete deck supported by Hybrid Composite Beams. Each beam is comprised of a glassfiber reinforced polymer (FRP) box shell containing a tied parabolic concrete arch. Inclined stirrups provide shear integrity and enforce composite action between the HCBs and the concrete deck. This paper focuses on evaluating the in-service performance of a newly constructed HCB bridge superstructure located on Route 205 in Colonial Beach, Virginia. A live load test was conducted using tandem axle dump trucks under both quasi-static and dynamic conditions. Results obtained from the experimental investigation were used to determine three key behavior characteristics. Dynamic amplification and lateral load distribution were found to be reasonable in comparison to the assumed design values. The testing program also included internal and external measurement systems to help characterize the load sharing behavior of the HCB on an element level. The main load carrying elements are the deck in compression and the steel ties in tension, and the FRP shell did not act compositely with the internal components.
In this paper, we found new exact solutions to the Einstein- Maxwell system of equations within the framework of MIT Bag Model considering a particular form for the measure of anisotropy and a gravitational potential which depends on an adjustable parameter α. Variables as the energy density, radial pressure, tangential pressure, electric field intensity and the metric functions are written in terms of elementary and polinominal functions. We show that the form chosen for the gravitational potential and the anisotropy allows obtain physically acceptable solutions with any value of the adjustable parameter.
We investigate the decay of an arbitrary neutral boson into a pair of on-shell W-bosons in a magnetic field. The possible existence of the new neutral bosons with the spins 0, 2, 3 and with the charge conjugation C=+1 in the energy (mass) range from zero to 160.77 GeV is predicted. The analyses show that the existence of the neutral boson with the spin 2 in the energy (mass) range from zero to 160.77 GeV is more promising and realistic.
In the article it is shown that at presence of fundamental scalar fields determining the masses of the scalar charged particles the global thermodynamic equilibrium (GTE) is compatible with a process of the cosmological expansion of the statistical system.
We study warm inflationary universe model on the BIon in thermal background. The BIon is a configuration in flat space of a D-brane and a parallel anti-D-brane connected by a wormhole with F-string charge. When the branes and antibranes are well separated and the brane's spike is far from the antibrane's spike, wormhole isn't formed however when two branes are close to each other, they can be connected by a wormhole. In this condition, there exists many channels for flowing energy from extra dimensions into our universe and inflation may naturally occur in a warm region. We present a model that allows all cosmological parameters like the scale factor $a$, the Hubble parameter $H$ and universe energy density depend on the shape function and temperature of wormhole in transverse dimension between two branes. In our model, the expansion of 4D universe is controlled by the thermal wormhole between branes and ends up in Big-Rip singularity. We show that at this singularity, universe would be destroyed and one black F-string formed. Finally, we test our model against WMAP, Planck and BICEP2 data and obtain the ripping time. According to experimental data, $N\simeq 50$ case leads to $n_{s}\simeq 0.96$, where \emph{N} and $n_{s}$ are the number e-folds and the spectral index respectively. This standard case may be found in $0.01 < R_{Tensor-scalar } < 0.3$, where $R_{Tensor-scalar }$ is the tensor-scalar ratio. At this point, the finite time that Big Rip singularity occurs is $t_{rip}=29(Gyr)$ for WMAP and Planck data and $t_{rip}=27.5(Gyr)$ for BICEP2 data. Comparing this time with the time of Big Rip in brane-antibrane, we find that the wormhole in BIonic system accelerates the destruction of the universe.
It is taken into account that not the Ricci tensor ${R_{il}}$ (Einstein equation), but the Riemann tensor ${R_{iklm}}$ provides the most general description of the space geometry. If ${R_{il}=0}$ (the space empty with matter, but it can be occupied by gravitational waves) then ${R_{iklm}={C_{iklm}}} $ . The tensor ${C_{iklm}}$ is the Weyl tensor, which disappears by conversion:${R_{il}={g^{km}}{R_{iklm}}}$ and we lose all information about the space structure, which is described by ${C_{iklm}}$ .The symmetry of ${R_{il}}$ provides the existents of gravitational waves with the spin s=2. We show that ${C_{iklm}}$ describes gravitational waves with s=1. Such gravitational waves can be created in inhomogeneous media, where the selected directions are determined by derivates of the energy-momentum tensor ${T^m}_{i,k}$ of matter. It is taken into account that gravitation is described not only by the metric tensor $g^{ik} = (1/2)(γ^i γ^k + γ^k γ^i)$, but also by the anti-symmetric tensor $σ^{ik} = (i/2)({γ^i}{γ^k} - {γ^k}{γ^i})$, where ${γ^k}(x)$ are Clifford matrices. We show that the tensor ${K_{ik}} = (1/4){σ^{lm}} {R_{iklm}}$, is the anty-simmetric analog to the Ricci tensor. The ${K_{lm}}$ describes various kinds of space metrics, not described by the Ricci tensor. It includes the Weyl tensor ${C_{iklm}}$, because $σ^{lm} {C_{lmik}}$ is not zero.
Bohmian mechanics solves the wave-particle duality paradox by introducing the concept of a physical particle that is always point-like and a separate wavefunction with some sort of physical reality. However, this model has not been satisfactorily extended to relativistic levels. Here we introduce a model of permanent point-like particles that works at any energy level. Our model seems to have the benefits of Bohmian mechanics without its shortcomings. We propose an experiment for which the standard interpretation of quantum mechanics and our model make different predictions.
This article considers an opportunity of disinfecting a part of the Earth surface, occupying a large area of ten thousand square kilometers. The sunlight will cause dissociation of molecular bromine into atoms; each bromine atom kills thirty thousand molecules of ozone. Each bromine plate has a mass of forty milligrams grams and destroys ozone in the area of hundred square meters. Thus, to form the ozone hole over the area of ten thousand square kilometers, it is required to have the total mass of bromine equal to the following four tons.
The aim of the present dissertation is to analyze the meaning of the entropy bounds of the holographic sector once tested for statistical ensembles of particles, in order to deeper investigate the nature of these constraints and their mutual links. From the Universal Energy Bound (UEB) simple time constraints can be argued, which are manifestations of the discrete nature of the space-time and of the presence of ultimate space-time scales. From the combined effort of the UEB and of the Holographic bound by 't Hooft and Susskind, an entropy density bound as a function of temperature is achieved.
Klein-Gordon equation is derived for a particle in the brane model of Universe. It is compared with squared Dirac-Fock-Ivanenko equation and expression for a chiral current is obtained by this comparison. This expression defines chiral current through variation of spin connection gauge field that arises due to the symmetry in respect to local Lorenz transformations. So, the second derivative of gravitational gauge field determines variation of chiral current responsible for variation of mass. The role of these processes on the early stages of Universe evolution is discussed.
A recent paper by Harmut Traunmüller shows that the most adequate equation to interpret the observations on magnitude and redshift from 892 type 1a supernovae would be mu = 5 log[(1+z) ln(1+z)] + const. We discuss this result which is exacly the one we have obtained few years ago when postulating a relation between the speed of light and the expansion of the universe. We also compare our analytical result to the conclusion of Marosi who studied 280 supernovae and gamma-ray bursts in the range 0.1014 < z < 8.1. The difference between his results and ours is at worst of 0.3 %.
It is the goal of this article to extend the notion of quantization from the standard interpretation focused on non-commuting observables defined starting from classical analogues, to the topological equivalents defined in terms of coefficient groups in (co)homology. It is shown that the commutation relations between quantum observables become (non)compatibility relations between coefficient groups. The main result is the construction of a new, higher-level form of quantization, as seen from the perspective of the universal coefficient theorem. This idea brings us closer to a consistent quantization of gravity, allows for a systematic description of topology changing string interactions but also gives new, quantum-topological degrees of freedom in discussions involving quantum information. On the practical side, a possible connection to the fractional quantum Hall effect is explored.