In the present work we study the scale-dependence of polytropic non-charged black holes in (3+1)-dimensional space-times assuming a cosmological constant. We allow for scale-dependence of the gravitational and cosmological couplings, and we solve the corresponding generalized field equations imposing the null energy condition. Besides, some properties, such as horizon structure and thermodynamics, are discussed in detail.

In the present work we study the scale dependence at the level of the effective action of charged black holes in Einstein-Maxwell as well as in Einstein-powerMaxwell theories in (2 + 1)-dimensional spacetimes without a cosmological constant. We allow for scale dependence of the gravitational and electromagnetic couplings, and we solve the corresponding generalized field equations imposing the null energy condition. Certain properties, such as horizon structure and thermodynamics, are discussed in detail.

In this work we present a regular black hole solution, in the context of scale-dependent General Relativity, satisfying the weak energy condition. The source of this solution is an anisotropic effective energy-momentum tensor which appears when the scale dependence of the theory is turned-on. In this sense, the solution can be considered as a semiclassical extension of the Schwarzschild one.

The dynamics of the O + OH reaction on the ground state potential energy surface (PES) is investigated by means of the quasiclassical trajectory method and two statistical methods: phase space theory and statistical quantum method. Preliminary calculations with an exact quantum method are also reported. The quasiclassical trajectory calculations show evidence for a phase space bottleneck inhibiting the intramolecular energy transfer between the O-H and O-O bonds. As a result, the probability of the intermediate complex dissociating back toward the reactants is high, thereby yielding a reaction probability significantly lower than expected for a barrierless and exothermic reaction. The features of the PES, which are the cause of this dynamical effect, are identified. This is essentially the conservation of the equilibrium distance of the O-H bond, hardly changed by a close encounter with an oxygen atom. The statistical calculations, which do not take into account the PES in the complex region, yield a high reaction probability, much larger than the probability calculated from the dynamical methods, both classical and quantum. If the statistical cross sections are corrected by a scaling factor, which corresponds actually to scaling the capture probability, then a good agreement is observed between dynamical and statistical calculations of the product state distributions. The differential cross sections calculated with all the methods show a backward-forward symmetry, with sharp polarization peaks. The complex lifetime is divided into two parts by the bottleneck. During the first part, the system remains trapped in a small region of the phase space and has a high probability to dissociate back toward the reactants. This is a nonstatistical effect due to the PES shape. During the second part, fast intramolecular vibrational energy redistribution takes place, leading to a statistical distribution of energy on the rovibrational states of the products. These findings indicate that the O + OH reaction has mixed dynamics, both with statistical and nonstatistical aspects.