An analytic estimation of the mass function for gravitationally bound objects is presented. We use the Zel’dovich approximation to extend the Press-Schecter analysis to nonspherical collapse. For the Zel’dovich approximation, the gravitational collapse along all three directions which will eventually lead to the formation of real virialized objects clumps occurs in the regions where the lowest ...

The separate contributions to cosmology of the above researchers are revisited and a cosmology encompassing their basic ideas is proposed. We study Dirac’s article on the large number hypothesis (Proc.Roy.Soc. Lon. A 165,199; 1938), Sciama’s proposal of realizing Mach’s principle (MNRAS 113, 34; 1953), and Robert Dicke’s considerations on an ‘electromagnetic’ theory of gravitation with a variab...

We permanently deal with gravity force. Experimental evidences revealed that moving against gravity strongly differs from moving along the gravity vector. This directional asymmetry has been attributed to an optimal planning process that optimizes gravity force effects to minimize energy. Yet, only few studies have considered the case of vertical movements in the context of optimal control. Wha...

Gravitational search algorithm (GSA) is based on the law of gravity and a mass of interaction. In GSA, the searcher agents are a collection of masses which interact with each other based on the Newtonian gravity and the laws of motion. This paper proposes a new clustered gravitational search algorithm (CGSA) to accelerate the performance of the GSA. Here, the whole population is divided into th...

Response of adductor longus (AL) muscle to gravitational unloading and reloading was studied. Male Wistar Hannover rats (5-wk old) were hindlimb-unloaded for 16 days with or without 16-day ambulation recovery. The electromyogram (EMG) activity in AL decreased after acute unloading, but that in the rostral region was even elevated during continuous unloading. The EMG levels in the caudal region ...

This paper aims at optimizing the parameters involved in stress analysis of perforated plates, in order to achieve the least amount of stress around the square-shaped holes located in a finite isotropic plate using metaheuristic optimization algorithms. Metaheuristics may be classified into three main classes: evolutionary, physics-based, and swarm intelligence algorithms. This research uses Ge...

The Strength Pareto Gravitational Search Algorithm (SPGSA) to solve Economic Load Dispatch (ELD) is presents this paper with various generator constraints in power systems. The ELD problem in a power system is to determine the optimal combination of power outputs for all generating units which will minimize the total fuel cost while satisfying all practical constraints. For practical generator ...

A hypothetical time variation of the gravitational constant G would cause neutron star matter to depart from beta equilibrium, due to the changing hydrostatic equilibrium. This induces nonequilibrium beta processes, which release energy that is invested partly in neutrino emission and partly in internal heating. Eventually, the star arrives at a stationary state in which the temperature remains...

Proposals that quantum gravity gives rise to non-commutative spacetime geometry and deformations of Poincaré symmetry are examined in the context of (2+1)dimensional quantum gravity. The results are expressed in five lessons, which summarise how the gravitational constant, Planck’s constant and the cosmological constant enter the non-commutative and non-cocommutative structures arising in (2+1)...

We present the spherical harmonic equation for the gravitational potential inside the Earth. The equation satisfies Poisson's equation and converges uniformly. It obviates the need for downward continuation of the exterior potential with its attendant convergence difficulties but of course requires some knowledge of the Earth's density distribution. Equipped with the equation, we derive the gen...