Институт теоретической физики им. Л.Д. Ландау РАН

L.D. Landau Institute for Theoretical Physics RAS

L.D. Landau Institute for Theoretical Physics RAS

Recent results on inflation and present dark energy

Date/Time: 12:00 24-Jun-2020

Abstract:

Recent results on inflation and present dark energy

Alexei A. Starobinsky

Landau Institute for Theoretical Physics RAS, Moscow - Chernogolovka, Russia

A brief review of papers published and submitted since the Khalatnikov-100 conference in October 2019 is presented. These papers can be divided into two groups: those on the investigation of dark energy in the present universe [1-5] and those on inflation and possible anisotropic stages preceding it [6-12]. In the former papers either some given fundamental models of present dark energy alternative to an exact cosmological constant are compared with the most recent observational data, or the reconstruction technique is used to obtain properties of dark energy directly from the observational data. In the latter papers different extensions of the simplest one–parametric inflationary models (the R+R^2 (Starobinsky) or Higgs ones) are investigated in order to test some local and non-local modifications of general relativity and to obtain new observable effects including local features in the power spectra of perturbations, primordial black holes and second-order primordial gravitational waves having a maximum at short scales.

1. M. Rossi, M. Ballardini, M. Braglia, F. Finelli, D. Paoletti, A. A. Starobinsky, C. Umilta. Cosmological constraints on post-Newtonian parameters in effectively massless scalar-tensor theories of gravity. Phys. Rev. D 100, no. 10, 103524 (2019); arXiv:1906.10218 [astro-ph.CO].

2. M. Ballardini, M. Braglia, F. Finelli, D. Paoletti, A. A. Starobinsky, C. Umilta. Scalar-tensor theories of gravity, neutrino physics, and the H_0 tension. JCAP, submitted (2020); arXiv:2004.14349 [astro-ph.CO].

3. B. L'Huillier, A. Shafieloo, D. Polarski, A. A. Starobinsky. Defying the laws of gravity I: Model-independent reconstruction of the Universe expansion from growth data. MNRAS. 494, No. 1, 819-826 (2020); arXiv:1906.05991 [astro-ph.CO].

4. R. Calderon, D. Felbacq, R. Gannouji, D. Polarski, A. A. Starobinsky. Global properties of the growth index of matter inhomogeneities in the Universe.

Phys. Rev. D 100, no. 8, 083503 (2019); arXiv:1908.00117 [astro-ph.CO].

5. R. Calderon, D. Felbacq, R. Gannouji, D. Polarski, A. A. Starobinsky. Some mathematical aspects of global properties of the growth index. Phys. Rev. D 101, No. 10, 103501 (2020); arXiv:1912.06958 [astro-ph.CO].

6. H. Motohashi, A. A. Starobinsky. Constant-roll inflation in scalar-tensor gravity. JCAP 1911 (2019) 025; arXiv:1909.10833 [gr-qc].

7. M. Braglia, D. K. Hazra, F. Fimelli, G. F. Smoot, L. Sriramkumar, A. A. Starobinsky. Generating PBHs and small-scale GWs in two-field models of inflation.

JCAP, submitted (2020); arXiv:2005.02895 [astro-ph.CO].

8. I. Debono, D. K. Hazra, A. Shafieloo, G. F. Smoot, A. A. Starobinsky. Constraints on features in the inflationary potential from future Euclid data. MNRAS, accepted (2020); arXiv:2003.05262 [astro-ph.CO].

9. A. A. Starobinsky, S. V. Sushkov, M. S. Volkov. Anisotropy screening in Horndeski cosmologies.Phys. Rev. D 101, No. 6, 064039 (2020); arXiv:1912.12320 [hep-th].

10. M. C. Pookkillath, A. De Felice, A. A. Starobinsky.

Anisotropic instability in a higher order gravity theory. JCAP, accepted (2020); arXiv:2004.03912 [gr-qc].

11. M. Ballardini, M. Braglia, F. Finelli, G. Marozzi, A. A. Starobinsky. Energy-momentum tensor and helicity for gauge fields coupled to a pseudo-scalar inflaton. Phys. Rev. D 100, no. 12, 123542 (2019); arXiv:1910.13448 [gr-qc].

12. A. S. Koshelev, K. S. Kumar, A. Mazumdar, A. A. Starobinsky. Non-Gaussianities and tensor-to-scalar ratio in nonlocal R^2-like inflation. J. High Energy Phys., (2020); arXiv:2003.00629 [hep-th].

Alexei A. Starobinsky

Landau Institute for Theoretical Physics RAS, Moscow - Chernogolovka, Russia

A brief review of papers published and submitted since the Khalatnikov-100 conference in October 2019 is presented. These papers can be divided into two groups: those on the investigation of dark energy in the present universe [1-5] and those on inflation and possible anisotropic stages preceding it [6-12]. In the former papers either some given fundamental models of present dark energy alternative to an exact cosmological constant are compared with the most recent observational data, or the reconstruction technique is used to obtain properties of dark energy directly from the observational data. In the latter papers different extensions of the simplest one–parametric inflationary models (the R+R^2 (Starobinsky) or Higgs ones) are investigated in order to test some local and non-local modifications of general relativity and to obtain new observable effects including local features in the power spectra of perturbations, primordial black holes and second-order primordial gravitational waves having a maximum at short scales.

1. M. Rossi, M. Ballardini, M. Braglia, F. Finelli, D. Paoletti, A. A. Starobinsky, C. Umilta. Cosmological constraints on post-Newtonian parameters in effectively massless scalar-tensor theories of gravity. Phys. Rev. D 100, no. 10, 103524 (2019); arXiv:1906.10218 [astro-ph.CO].

2. M. Ballardini, M. Braglia, F. Finelli, D. Paoletti, A. A. Starobinsky, C. Umilta. Scalar-tensor theories of gravity, neutrino physics, and the H_0 tension. JCAP, submitted (2020); arXiv:2004.14349 [astro-ph.CO].

3. B. L'Huillier, A. Shafieloo, D. Polarski, A. A. Starobinsky. Defying the laws of gravity I: Model-independent reconstruction of the Universe expansion from growth data. MNRAS. 494, No. 1, 819-826 (2020); arXiv:1906.05991 [astro-ph.CO].

4. R. Calderon, D. Felbacq, R. Gannouji, D. Polarski, A. A. Starobinsky. Global properties of the growth index of matter inhomogeneities in the Universe.

Phys. Rev. D 100, no. 8, 083503 (2019); arXiv:1908.00117 [astro-ph.CO].

5. R. Calderon, D. Felbacq, R. Gannouji, D. Polarski, A. A. Starobinsky. Some mathematical aspects of global properties of the growth index. Phys. Rev. D 101, No. 10, 103501 (2020); arXiv:1912.06958 [astro-ph.CO].

6. H. Motohashi, A. A. Starobinsky. Constant-roll inflation in scalar-tensor gravity. JCAP 1911 (2019) 025; arXiv:1909.10833 [gr-qc].

7. M. Braglia, D. K. Hazra, F. Fimelli, G. F. Smoot, L. Sriramkumar, A. A. Starobinsky. Generating PBHs and small-scale GWs in two-field models of inflation.

JCAP, submitted (2020); arXiv:2005.02895 [astro-ph.CO].

8. I. Debono, D. K. Hazra, A. Shafieloo, G. F. Smoot, A. A. Starobinsky. Constraints on features in the inflationary potential from future Euclid data. MNRAS, accepted (2020); arXiv:2003.05262 [astro-ph.CO].

9. A. A. Starobinsky, S. V. Sushkov, M. S. Volkov. Anisotropy screening in Horndeski cosmologies.Phys. Rev. D 101, No. 6, 064039 (2020); arXiv:1912.12320 [hep-th].

10. M. C. Pookkillath, A. De Felice, A. A. Starobinsky.

Anisotropic instability in a higher order gravity theory. JCAP, accepted (2020); arXiv:2004.03912 [gr-qc].

11. M. Ballardini, M. Braglia, F. Finelli, G. Marozzi, A. A. Starobinsky. Energy-momentum tensor and helicity for gauge fields coupled to a pseudo-scalar inflaton. Phys. Rev. D 100, no. 12, 123542 (2019); arXiv:1910.13448 [gr-qc].

12. A. S. Koshelev, K. S. Kumar, A. Mazumdar, A. A. Starobinsky. Non-Gaussianities and tensor-to-scalar ratio in nonlocal R^2-like inflation. J. High Energy Phys., (2020); arXiv:2003.00629 [hep-th].

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