We consider equilibrium models of spherical boson stars in Palatini f (Script R)= Script R+ ξ
Script R 2 gravity and study their collapse when perturbed. The Einstein-Klein-Gordon …

In this paper, metric-affine theories in which the gravity Lagrangian is built using (projectively
invariant) contractions of the Ricci tensor with itself and with the metric (Ricci-based gravity …

We construct a general class of modified Ellis-Bronnikov wormholes, where one asymptotic
Minkowski region is replaced by a bounded 2-sphere core, characterized by an asymptotic …

Considering the so-called Ricci-based gravity theories, a family of extensions of general
relativity whose action is given by a nonlinear function of contractions and products of the …

We show that the absence of unbounded algebraic curvature invariants constructed from
polynomials of the Riemann tensor cannot guarantee the absence of strong singularities. As …

We study the space-time geometry generated by coupling a free scalar field with a
noncanonical kinetic term to general relativity in (2+ 1) dimensions. After identifying a family …

In this dissertation, we review the most relevant properties of Einstein's theory of gravity and
modified theories of gravity. We address the fundamental principles and mathematical tools …

The absence of a well-established theory concerning gravity and its behavior at high
energies demands a global effort to construct a viable quantum theory for the gravitational …

Neste trabalho, discutimos como é possıvel estabelecer a equivalência entre teorias de
gravidade modificadas baseadas no tensor de Ricci e a relatividade geral. Inicialmente …