6533b852fe1ef96bd12ab6ca
RESEARCH PRODUCT
Renormalized stress-energy tensor for spin-1/2 fields in expanding universes
José Navarro-salasAdrián Del RíoFrancisco Torrentisubject
High Energy Physics - TheoryTensor contractionPhysicsNuclear and High Energy PhysicsCosmology and Nongalactic Astrophysics (astro-ph.CO)Quantum field theory in curved spacetimeFOS: Physical sciencesFísicaGeneral Relativity and Quantum Cosmology (gr-qc)General Relativity and Quantum CosmologyTensor fieldGeneral Relativity and Quantum CosmologyClassical mechanicsHigh Energy Physics - Theory (hep-th)De Sitter universeFour-tensorStress–energy tensorTensor densityScalar fieldAstrophysics - Cosmology and Nongalactic AstrophysicsMathematical physicsdescription
We provide an explicit expression for the renormalized expectation value of the stress-energy tensor of a spin-$1/2$ field in a spatially flat FLRW universe. Its computation is based on the extension of the adiabatic regularization method to fermion fields introduced recently in the literature. The tensor is given in terms of UV-finite integrals in momentum space, which involve the mode functions that define the quantum state. As illustrative examples of the method efficiency, we see how to compute the renormalized energy density and pressure in two interesting cosmological scenarios: a de Sitter spacetime and a radiation-dominated universe. In the second case, we explicitly show that the late-time renormalized stress-energy tensor behaves as that of classical cold matter. We also check that, if we obtain the adiabatic expansion of the scalar field mode functions with a similar procedure to the one used for fermions, we recover the well-known WKB-type expansion.
| year | journal | country | edition | language |
|---|---|---|---|---|
| 2014-01-01 |