Ronaldo V. Lobato

Analytical general solutions for static wormholes in

Originally proposed as a tool for teaching the general theory of relativity, wormholes are today approached in many different ways and are seeing as an efficient alternative for interstellar and time travel. Attempts to achieve observational signatures of wormholes have been growing as the subject has become more and more popular. In this article we investigate some f(R,T) theoretical predictions for static wormholes, i.e., wormholes whose throat radius can be considered a constant. Since the T-dependence in f(R,T) gravity is due to the consideration of quantum effects, a further investigation of wormholes in such a theory is well motivated. We obtain the energy conditions of static wormholes in f(R,T) gravity and apply an analytical approach to find their physical and geometrical solutions. We highlight that our results are in agreement with previous solutions and assumptions presented in the literature.

f(R,T)

The Anomalous X-ray Pulsars (AXPs) and Soft Gamma-ray Repeaters (SGRs) are a class of pulsars understood as neutron stars (NSs) with super strong surface magnetic fields, namely

gravity

B\gtrsim10^{14}

Magnetars and white dwarf pulsars

G, and for that reason are known as Magnetars. However, in the last years some SGRs/AXPs with low surface magnetic fields

Particle acceleration and radio emission for SGRs/AXPs as white dwarf pulsars

B\sim(10^{12}-10^{13})

White Dwarf Pulsars and Very Massive Compact Ultra Magnetized White Dwarfs

G have been detected, challenging the Magnetar description. Moreover, some fast and very magnetic white dwarfs (WDs) have also been observed, and at least one showed X-Ray energy emission as an ordinary pulsar. Following this fact, an alternative model based on white dwarfs pulsars has been proposed to explain this special class of pulsars. In this model, AXPs and SGRs as dense and magnetized white dwarfs can have surface magnetic field

Radio pulsar death lines to SGRs/AXPs and white dwarfs pulsars

B\sim 10^{7}-10^{10}

Ultra-high energy cosmic rays from white dwarf pulsars and the Hillas criterion

G and rotate very fast with frequencies

Strong magnetic fields and SGRs/AXPs as white dwarf pulsar: a source of ultra-high energy cosmic rays

\Omega\sim 1

Stellar equilibrium configurations of white dwarfs in the f(R, T) gravity

rad/s, consistent with the observed rotation periods