The vacuum expectation value of the spinor massive field in the cosmic string spacetime

Abstract

We found the contribution to the vacuum expectation value of the energy-momentum tensor of a massive Dirac field due to the conical geometry of the cosmic string space-time. The heat kernel and heat kernel expansion for the squared Dirac operator in this background are also considered and the first three coefficients were found in an explicity form.

Transition processes of a static multilevel atom in the cosmic string spacetime with a conducting plane boundary

“…It has been manifested that the nontrivial spacetime structure due to the string can give rise to several remarkable physical effects, for example, electron-positron pair production by a high energy photon 28,29 , bremsstrahlung process of a freely moving charged particle 30,31 , self-force on a static electrically charged particle 32 , gravitational lensing effect 33 and gravitational Aharonov-Bohm effect 34–36 , etc. Furthermore, in order to fully uncover the properties of the string, some important quantum processes that were explicitly investigated in the Minkowski spacetime have been increasingly extended to the case in the presence of the string, e.g., vacuum polarization 37–39 , Landau quantization 40 , Berry phase 41,42 , the Casimir effect 43,44 and the Casimir-Polder interaction 45–47 . In the respect of the atomic radiative properties, let us list some previous works.…”

Uma discussão sistemática sobre as cordas cósmicas e o modelo de vórtices abelianos proposto por Nielsen e Olesen

“…Estes efeitos de polarização do vácuo 2 , na teoria quântica de campos, induzidos por uma estrutura cônica, foram alvos de muitos trabalhos publicados. Na análise especifica para o VEV do tensor energia-momento T µ ν , por exemplo, podemos observar vários trabalhos publicados, levando em consideração o caso para campos escalares [14][15][16][17][18][19] e campos fermiônicos [20][21][22][23][24] interagindo com campos vetoriais [24]. Outro observável físico induzido, devidoà presença desse defeito,é a densidade de corrente e carga, que servirá como fonte para as equações de Maxwell.…”

Induced vacuum bosonic current in a compactified cosmic string spacetime

“…Due to its lack of global flatness, the cosmic string spacetime modifies the vacuum fluctuations associated with quantum fields. In this sense it has been shown a non-vanishing results for the renormalized vacuum expectation value (VEV) of physical observables, like the energymomentum tensor, considering scalar and fermionic quantum fields in [16][17][18][19][20] and [21][22][23][24], respectively. Moreover, if we take into consideration the presence of a magnetic flux running along the string's core, additional contributions to the above VEVs associated with charged fields takes place.…”