We consider the Friedmann-Robertson-Walker cosmologies of theories of gravity that generalise the Einstein-Hilbert action by replacing the Ricci scalar, R, with some function, f(R). The general asymptotic behaviour of these cosmologies is found, at both early and late times, and the effects of adding higher and lower powers of R to the Einstein-Hilbert action is investigated. The assumption tha...

Data mining is a process of discovering and exploiting hidden patterns from data. Clustering as an important task of data mining divides the observations into groups (clusters), which is according to the principle that the observations in the same cluster are similar, and the ones from different clusters are dissimilar to each other. Subspace clustering enables clustering in subspaces within a ...

We propose a mathematical model for vision-based autonomous navigation on general terrains. Our model, a generalization of Mallot’s inverse perspective, assumes the direction of gravity and the speed of the mobile agent to be known, thus combining visual, inertial, and navigational information into a coherent scheme. Experiments showing the viability of this approach are presented and a sensiti...

Einstein’s general theory of relativity [1] is a successful classical theory of gravitation inasmuch as it agrees with all experimental data available at present [2]. To develop a microphysical gravitation theory, it may prove useful to investigate the extent to which the basic physical tenets of general relativity conform with the fundamental principles of the quantum theory. This is the gener...

It is assumed that the primary interaction between two masses m1 and m2 is not attractive as postulated by Newton’s law of gravitation, but repulsive. Both m1 and m2 emit and absorb gravitational radiation. Corresponding to the laws of optics the absorption is connected with an impulse transfer that produces the repulsive force. If, however, m1 and m2 are embedded in the gravitational radiation...

We suggest to consider the spacetime as a non-equilibrium system with a long-term stationary state that possess as a spatio-temporally fluctuating quantity β. These systems can be described by a superposition of several statistics, “superstatistics”. We propose a Gamma distribution for f(β) that depends on a parameter pl. By means of it the corresponding entropy is calculated, pl is identified ...

A discussion of the number of degrees of freedom, and their dynamical properties, in higher derivative gravitational theories is presented. It is shown that non-vanishing (Cmnpq) 2 terms arise in N=1, D=4 superstring Lagrangians due to one-loop radiative corrections with light field internal lines. 1 Bosonic Gravitation The usual Einstein theory of gravitation involves a symmetric tensor gμν wh...

The interaction of mass will determine the curvature of space-time, may determine that events proceed at different rates of time at each point in space, so each has a corresponding gravitational potential time. So we can find different values of gravity (g), corresponding to different times (t), thus making a "map of time in space." The space-time is curved by present mass, causing a force of a...

A discussion of the field content of quadratic higher-derivative gravitation is presented, together with a new example of a massless spin-two field consistently coupled to gravity. The full quadratic gravity theory is shown to be equivalent to a canonical secondorder theory of a massive scalar field, a massive spin-two symmetric tensor field and gravity. The conditions showing that the tensor f...