We present a detailed analysis of AdS3 gravity, the BTZ black hole and the associated conformal field theories (CFTs). In particular we focus on the non-extreme six-dimensional string solution with background metric AdS3×S near the horizon. In addition we introduce momentum modes along the string, corresponding to a BTZ black hole, and a Taub-NUT soliton in the transverse Euclidean space. We sh...

In quantum gauge theory of gravity, the gravitational field is represented by gravitational gauge field. The field strength of gravitational gauge field has both gravitoelectric component and gravitomagnetic component. In classical level, gauge theory of gravity gives out classical Newtonian gravitational interactions in a relativistic form. Besides, it gives out gravitational Lorentz force whi...

We show that the equations of motion of two-dimensional dilaton gravity conformally coupled to a scalar field can be reduced to a single nonlinear second-order partial differential equation when the coordinates are chosen to coincide with the two scalar fields, the matter field f and the dilaton φ, which are present in the theory. This result may help solve and understand twoand higher-dimensio...

We show that classically scale invariant gravity coupled to a single scalar field can undergo dimensional transmutation and generate an effective Einstein-Hilbert action for gravity, coupled to a massive dilaton. The same theory has an ultraviolet fixed point for coupling constant ratios such that all couplings are asymptotically free. However the catchment basin of this fixed point does not in...

We present a new group field theory for 4D quantum gravity. It incorporates the constraints that give gravity from BF theory and has quantum amplitudes with the explicit form of simplicial path integrals for first-order gravity. The geometric interpretation of the variables and of the contributions to the quantum amplitudes is manifest. This allows a direct link with other simplicial gravity ap...

The renormalization group flow of the worldvolume theory depends very much from the number of unbroken supersymmetries. In the dual AdS picture we break supersymmetry by adding different types of BPS black holes. We argue, that this BPS black hole causes a non-trivial renormalization group flow in the worldvolume field theory and especially a regular horizon translates into a nontrivial IR fixp...

Doppler data generated with the Cassini spacecraft’s radio carrier waves at Xand Ka-bands can be used to determine the quadrupole moments of Rhea’s gravitational field. The resulting tri-axial field should be consistent with the assumption that Rhea is in tidal and rotational equilibrium. If so, we can construct interior models that are consistent with Rhea’s mean density of 1236 kg/m3, determi...

We investigate the weak gravity bounds on the U(1) gauge theory and scalar field theories in various dimensional noncommutative space. Many results are obtained, such as the upper bound on the noncommutative scale gYMMp for four dimensional noncommutative U(1) gauge theory. We also discuss the weak gravity bounds on their commutative counterparts. For example, our result on 4 dimensional noncom...

We introduce 2D potential field migration for the interpretation of gravity gradiometry data. This method is based on a direct integral transformation of the observed gravity gradients into subsurface density distributions which can be used for realtime imaging or as an a priori model for subsequent 3D regularized inversion. Potential field migration is very fast and stable with respect to nois...

The wave type field equation θ = λθ, where θ is a coframe field on a space-time, was recently proposed to describe the gravity field. This equation has a unique static, spherical-symmetric, asymptotically-flat solution, which leads to the viable Yilmaz-Rosen metric. We show that the wave type field equation is satisfied by the pseudo-conformal frame if the conformal factor is determined by a sc...