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SUMMARY:SPACE seminar: Mariam Abdelaziz - "Inflation without an Inflaton"
DTSTART:20260505T100000Z
DTEND:20260505T110000Z
DTSTAMP:20260530T150900Z
UID:indico-event-17790@indico.global
DESCRIPTION:\nSpeaker:  Mariam Abdelaziz  (SSM)\nAbstract: Inflation is 
 remarkably successful at addressing the main shortcomings of the Big Bang 
 picture\, explaining the observed large-scale homogeneity and isotropy of 
 the Universe\, and generating the primordial seeds from which cosmic struc
 ture later formed. In the standard picture\, these seeds arise from quantu
 m vacuum fluctuations of a scalar inflaton field. Yet this success comes w
 ith a price: different choices of the inflaton potential lead to many poss
 ible realizations of inflation\, making the framework highly model depende
 nt. This naturally motivates a broader question: can inflation be realized
  without introducing an inflaton at all? In this talk\, I will discuss the
  “Inflation without an Inflaton (IWI)” scenario\, in which accelerated
  expansion takes place in an exact de Sitter background and scalar perturb
 ations are generated instead as second-order effects of tensor metric fluc
 tuations\, namely primordial gravitational waves. I will introduce the bas
 ic idea behind this framework\, present its prediction for the scalar powe
 r spectrum\, and discuss recent progress in understanding the intrinsic pr
 imordial non-Gaussianity of the scalar fluctuations it produces.\nReferenc
 es:\n\n%\\cite{Bertacca:2024zfb} \\bibitem{Bertacca:2024zfb} D.~Bertacca\,
  R.~Jimenez\, S.~Matarrese and A.~Ricciardone\, %``Inflation without an in
 flaton\,'' Phys. Rev. Res. \\textbf{7}\, no.3\, L032010 (2025) doi:10.1103
 /vfny-pgc2 [arXiv:2412.14265 [astro-ph.CO]]. %6 citations counted in INSPI
 RE as of 20 Apr 2026D.~Bertacca\, R.~Jimenez\, S.~Matarrese and A.~Ricciar
 done\,%``Inflation without an inflaton\,''Phys. Rev. Res. \\textbf{7}\, no
 .3\, L032010 (2025)doi:10.1103/vfny-pgc2[arXiv:2412.14265 [astro-ph.CO]].%
 \\cite{Bertacca:2024zfb} \\bibitem{Bertacca:2024zfb} D.~Bertacca\, R.~Jime
 nez\, S.~Matarrese and A.~Ricciardone\, %``Inflation without an inflaton\,
 '' Phys. Rev. Res. \\textbf{7}\, no.3\, L032010 (2025) doi:10.1103/vfny-pg
 c2 [arXiv:2412.14265 [astro-ph.CO]]. %6 citations counted in INSPIRE as of
  20 Apr 2026%\\cite{Bertacca:2024zfb} \\bibitem{Bertacca:2024zfb} D.~Berta
 cca\, R.~Jimenez\, S.~Matarrese and A.~Ricciardone\, %``Inflation without 
 an inflaton\,'' Phys. Rev. Res. \\textbf{7}\, no.3\, L032010 (2025) doi:10
 .1103/vfny-pgc2 [arXiv:2412.14265 [astro-ph.CO]]. %6 citations counted in 
 INSPIRE as of 20 Apr 2026Bertacca\, R. Jimenez\, S. Matarrese and A. Ricci
 ardone\, Inflation without an inflaton\, Phys. Rev. Res. 7\, L032010 (2025
 ) [arXiv:2412.14265 [astro-ph.CO]].\nM. Traforetti\, M. Abdelaziz\, D. Ber
 tacca\, R. Jimenez\, S. Matarrese and A. Ricciardone\, Inflation without a
 n inflaton. II. Observational predictions\, Phys. Rev. D 113\, 023553 (202
 6) [arXiv:2511.11808 [astro-ph.CO]].\nM. Abdelaziz\, M. Traforetti\, D. Be
 rtacca\, R. Jimenez\, S. Matarrese and A. Ricciardone\, Inflation without 
 an Inflaton III: non-Gaussian signatures\, [arXiv:2603.15036 [astro-ph.CO]
 ].\n\n \n\nZoom link: click here\n\nhttps://indico.global/event/17790/
LOCATION:San Marcellino (Aula 4)
URL:https://indico.global/event/17790/
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