38
P. K. Suresh
ary models and it appears that quantum gravity effect cannot be fully accounted for
its compatibility with observed results. On the other hand, the lower multipole region
of the BB mode spectrum lies within the observed limit of the BK15 and Planck 2018
joint data. Therefore, it may be concluded that the reduction of the power of the BB
mode spectrum of the CMB, especially for the lower multipole less than 150, can be
considered as the signature of the quantum gravity. Further, from the analysis of the
quantum gravity effect on the lensed BB mode correlation angular power spectrum
of CMB with BK15 and Planck 2018 joint data, it may be concluded that the chaotic
inflationary models cannot be ruled out.
The values of HDO parameter relevant to each inflation model considered in the
present study are constrained with tensor-to-scalar ratio estimated from various current observed results of the CMB. However, the tensor-to-scalar ratio may be further
restricted to the estimate of the upcoming CMB observations such as PICO, CMBS4, etc. Therefore, the value of the HDO parameter may be constrained further with
the upcoming missions of CMB and may be useful to examine various inflationary models. Thus, the results of the present study may be useful in validating the
inflationary model and hopefully quantum gravity also.
In the present work, we examined the signature of quantum gravity on the BB
angular power spectrum through the chaotic inflationary models only. However, one
can re-examine the effect of quantum gravity with other inflationary models as well
as with the other theories of quantum gravity which is beyond the scope of the present
work.
Acknowledgements P K S acknowledges the financial support of DST-SERB, New Delhi. Author
would like to thank Dr. Rizwan Ul Haq Ansari for the wonderful discussions. Author acknowledges
the use of CAMB code and thanks Planck and BICEP team and websites for the data.
References
1. A.H. Guth, Phys. Rev. D 23, 347 (1981)
2. R.H. Brandenberger, IPM School on Cosmology 1999. arXiv:hep-ph/9910410v1 (1999)
3. A.D. Linde, Particle Physics and Inflationary Cosmology (CRC Press, 1990)
4. A.D. Linde, Lect. Notes Phys. 738, 1 (2008)
5. A.D. Linde, Phys. Letts. B 129, 177 (1983)
6. A.H. Guth, S.Y. Pi, Phys. Rev. Lett. 49, 1110 (1982)
7. A.D. Linde, Phys. Rev. D 49, 748 (1994)
8. J. Garcia-Bellido, A.D. Linde, Phys. Rev. D 57, 6075 (1998)
9. S. Dodelson, Modern Cosmology (Academic Press, 2003)
10. S. Dodelson, W.H. Kinney, E.W. Kolb, Phys. Rev. D 56, 3207 (1997)
11. P.A.R. Ade et al., Phys. Rev. Lett. 112, 241101 (2014)
12. D.H. Lyth, Phys. Rev. Lett. 78, 1861 (1997)
13. X. Calmet, V. Sanz, Phys. Lett. B 737, 12 (2014)
14. J.F. Donoghue, AIP. Conf. Proc. 1483, 73 (2012)
15. N. Agarwal, R.H. Ribeiro, R. Holman, JCAP 06, 016 (2014)
16. H. Collins, R. Holman, T. Vardanyan. arXiv:1403.4592 [hep-th]
17. P.A.R. Ade et al., Phys. Rev. Lett. 121, 221301 (2018)
P. K. Suresh
ary models and it appears that quantum gravity effect cannot be fully accounted for
its compatibility with observed results. On the other hand, the lower multipole region
of the BB mode spectrum lies within the observed limit of the BK15 and Planck 2018
joint data. Therefore, it may be concluded that the reduction of the power of the BB
mode spectrum of the CMB, especially for the lower multipole less than 150, can be
considered as the signature of the quantum gravity. Further, from the analysis of the
quantum gravity effect on the lensed BB mode correlation angular power spectrum
of CMB with BK15 and Planck 2018 joint data, it may be concluded that the chaotic
inflationary models cannot be ruled out.
The values of HDO parameter relevant to each inflation model considered in the
present study are constrained with tensor-to-scalar ratio estimated from various current observed results of the CMB. However, the tensor-to-scalar ratio may be further
restricted to the estimate of the upcoming CMB observations such as PICO, CMBS4, etc. Therefore, the value of the HDO parameter may be constrained further with
the upcoming missions of CMB and may be useful to examine various inflationary models. Thus, the results of the present study may be useful in validating the
inflationary model and hopefully quantum gravity also.
In the present work, we examined the signature of quantum gravity on the BB
angular power spectrum through the chaotic inflationary models only. However, one
can re-examine the effect of quantum gravity with other inflationary models as well
as with the other theories of quantum gravity which is beyond the scope of the present
work.
Acknowledgements P K S acknowledges the financial support of DST-SERB, New Delhi. Author
would like to thank Dr. Rizwan Ul Haq Ansari for the wonderful discussions. Author acknowledges
the use of CAMB code and thanks Planck and BICEP team and websites for the data.
References
1. A.H. Guth, Phys. Rev. D 23, 347 (1981)
2. R.H. Brandenberger, IPM School on Cosmology 1999. arXiv:hep-ph/9910410v1 (1999)
3. A.D. Linde, Particle Physics and Inflationary Cosmology (CRC Press, 1990)
4. A.D. Linde, Lect. Notes Phys. 738, 1 (2008)
5. A.D. Linde, Phys. Letts. B 129, 177 (1983)
6. A.H. Guth, S.Y. Pi, Phys. Rev. Lett. 49, 1110 (1982)
7. A.D. Linde, Phys. Rev. D 49, 748 (1994)
8. J. Garcia-Bellido, A.D. Linde, Phys. Rev. D 57, 6075 (1998)
9. S. Dodelson, Modern Cosmology (Academic Press, 2003)
10. S. Dodelson, W.H. Kinney, E.W. Kolb, Phys. Rev. D 56, 3207 (1997)
11. P.A.R. Ade et al., Phys. Rev. Lett. 112, 241101 (2014)
12. D.H. Lyth, Phys. Rev. Lett. 78, 1861 (1997)
13. X. Calmet, V. Sanz, Phys. Lett. B 737, 12 (2014)
14. J.F. Donoghue, AIP. Conf. Proc. 1483, 73 (2012)
15. N. Agarwal, R.H. Ribeiro, R. Holman, JCAP 06, 016 (2014)
16. H. Collins, R. Holman, T. Vardanyan. arXiv:1403.4592 [hep-th]
17. P.A.R. Ade et al., Phys. Rev. Lett. 121, 221301 (2018)