Extension of the adiabatic regularization method to spin-1/2 fields

Spanish Relativity Meeting: almost 100 years after Einstein's revolution

Landete, Aitor^1

Instituto de Física Teórica, UAM-CSIC, Universidad Autonoma de Madrid, Cantoblanco, Madrid

28049, Spain^1

关键词: Adiabatic expansion;    Expectation values;    Particle numbers;    Regularization methods;    Renormalization methods;    Scalar fields;    Stress-energy tensor;    Type expansions;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/600/1/012021/pdf
DOI  :  10.1088/1742-6596/600/1/012021

来源: IOP

【 摘 要 】

The adiabatic regularization method was designed by L. Parker [1] for scalar fields in order to to subtract the potentially UV divergences that appear in the particle number operator. After that the method was generalized [2] to remove, in a consistent way, the UV divergences that appear in the expectation value of the stress-energy tensor 〈Tμv〉 in homogeneous cosmological backgrounds. We are going to provide here the extension of the adiabatic regularization method to spin-1/2 fields first given in [3]. In order to achieve this extension we will show the generalization of the adiabatic expansion for fermionic fields which differs significantly from the WKB-type expansion that works for the scalar modes. We will also show the consistency of the extended method computing well-known results, computed by other renormalization methods for a Dirac field in a FLRW spacetime, like the conformal and axial anomalies. Finally we will compute the expectation value of the stress-energy tensor for a Dirac field in a de Sitter spacetime.