BPU 12 Congress

A Two-Field Model for Cosmological Inflation

10 Jul 2025, 17:50

20m

Politechnica Univ

Oral Presentations S05 – High Energy, Particle Physics, Gravitation and Cosmology High Energy, Particle Physics, Gravitation and Cosmology

Speaker

Dragoljub Dimitrijević (Faculty of Sciences and Mathematics, University of Niš, Serbia)

Description

We study cosmological inflation with two real scalar fields. We start from one scalar field with the DBI-type Lagrangian, which is of non-canonical form This scalar field can be related to a perfect fluid which describes (dominant) matter in the Universe at a time of interest.

We then extend the model introducing auxiliary real scalar field. The second field does not carry any dynamics, i.e. the equation of motion (at the background level) for the first field will not change.

Finally, we promote the second field to be dynamical, adding its kinetic term. This model, with now two dynamical fields is used to study cosmological inflation. We discuss scalar cosmological perturbation and estimate the scalar spectral index for the two-field model.

References:
[1] D. Dimitrijevic, M. Dimitrijevic, G. Djordjevic, and M. Milosevic, AIP Conference Proceedings 2071, 020008 (2019).
[2] D. Langlois and S. Renaux-Petel, JCAP 0804, 017 (2008).
[3] C. M. Peterson and M. Tegmark, Physical Review D, 83(2):023522 (2011).