The neutrino cooling and gamma heating rates are considered as an important
input needed to study the final phases of the evolution of high-mass stars. The
weak-interaction mediated processes, namely the $\beta$-decay and electron
capture, significantly change the lepton to baryon ratio and accelerate the
contraction of the core. The emission of resulting neutrinos/antineutrinos
tends to cool the stellar core. On the other hand, gamma rays are produced
because of electron capture and $\beta$-decay to excited states in daughter
nuclei. These gamma rays heat the core and contribute to an increase of entropy
which may cause convection to occur.
In the present work, the weak-interaction heating and cooling rates on a
chain of twenty-two isotopes of vanadium having mass in the range $43-64$ have
been estimated using the proton-neutron quasiparticle random phase
approximation theory. The rates have been computed for the temperature ranging
from ($10^{7} – 3 \times 10^{10}$)\;K and for the density range
($10-10^{11}$)\;g/cm$^{3}$. Our calculated neutrino energy loss rates have also
been compared with the previously reported rates calculated using other
theoretical models. At high stellar temperatures, our rates are larger by 1-2
orders of magnitude as compared to previous results.

Este artículo explora los viajes en el tiempo y sus implicaciones.

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