Haidar Sheikhahmadi

School of Astronomy, Institute for Research in Fundamental Sciences-IPM

Self-Interacting QFT in Curved Backgrounds, the Bubble Loop Corrections

Abstract:  We consider a general Lagrangian for a massive scalar field with a conformal coupling in the dS background and study the quantum corrections from bubble loop diagrams. Employing a dimensional regularization scheme, we calculate the regularized zero-point energy density, pressure, and the trace of the energy-momentum tensor. It is shown that the classical relation of trace for the vacuum stress-energy tensor receives quantum anomaly correction which depends on the mass and the conformal coupling, while the consistency relation of zero-point energy does hold. We calculate the density contrast associated with the vacuum zero-point energy and show that perturbations are of the order of background values indicate an inhomogeneous and non-perturbative distribution of the zero-point energy. Even more, we calculate the bispectrum associated with the distribution of the zero-point energy and pressure and show that they are highly non-Gaussian. In the next step, incorporating the perturbative in-in formalism, we extend our analysis to self-interacting fields with a general potential of even orders of the field. We again calculate the quantum corrections in the vacuum zero-point energy and pressure for these fields as well. We then investigate the equation of state corresponding to these quantum corrections and examine the scaling of the divergent terms in the vacuum zero-point energy and pressure associated with the dimensional regularization scheme. We discuss some interesting aspects of free and interacting vacua and their relation as well.

یکشنبه 6 خرداد 1403، ساعت 17:00

Sunday 26 May 2024 – 17:00 Tehran Time

Hybrid Seminar

دانشکده فیزیک – طبقه اول – کلاس فیزیک 3 Physics Department – first floor – Room Physics 3   /

https://vc.sharif.edu/ch/cosmology

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