IPM Positions

PostDoctoral Associate, School of Astronomy (2022 - Present )

Non IPM Affiliations

Post-Doctoral Associate of IASBS

Research Interests

Inflationary Cosmology, Perturbation Theory in Classic and Quantum Field Theory, General Relativity

Awards

According to my GPA 17.78, in the M.Sc. courses, I ranked second among 10 student • Member of scienti?c organizing committee of 19th Meeting on Research in Astronomy. [http://www.iasbs.ac.ir/seminar/physics/astro/astro19/committee.htm]. • Member of bright talents of University of Kurdistan • Member of Iran''''''''''''''''''''''''''''''''s National Elites Foundation • Editor in Export opinion on Astronomy and Astrophysics • Talent Member in the young researchers and elites club • Reviewer in Gravitation and Cosmology • Reviewer in Astrophysics Space Science • Reviewer in the International Journal of Physical Sciences. • Reviewer in the Open Astronomy Journal • Recently one of our paper Eur. Phys. J. C (2016) 76:66 [arXiv:1502.05952[astro-ph.CO]] selected as the Paper for Monday, Feb 23 2015 by Princeton university, [http://phn14.astro.princeton.edu/astroph- co?ee/archive/20150223].

Research Activities

My research focuses on the investigation of High Energy Regime (particularly In?ation, Zero Point Quantum Fluctuations and so on), Scalar-Tensor Models to justify dark energy (i.e. Brans Dicke, Chameleon, Quintessence, Tachyon and so on), Quantum Field Theory (QFT) in curved space time and also General Relativity (e.g. searching for new metrics in Black Holes studies, Teleparallel gravity and its role to unify the gravity and electromagnetism and etc.). I am particularly interesting in encoding the fundamental question "how universe began?". Well one knows several di?erent proposals to investigate such a problem were introduced up to now. For instance, one can refer to the Big Bang theory and beside that the Cyclic universe mechanism as most important and acceptable hypothesizes. Based on sentences mentioned above, I can summarize my interest to research in five areas as: 1. In?ationary universe (quantized and non-quantized scalar ?elds) 2. Observational tests and interacting mechanisms for scalar ?elds 3. High energy regime including quantum gravity, quantum ?uctuations, Casimir e?ect, black holes and so on 4. Non-commutative algebra 5. Cyclic universe List of Publications 1. H. Sheikhahmadi, “Comments on "Cosmic evolution in Brans-Dicke chameleon cosmology"[Eur. Phys. J. Plus (2011) 126: 80]” accepted for publication in ( Europian Physical Journal Plus, 2018). 2. H. Sheikhahmadi, E. N. Saridakis, A. Aghamohammadi, Kh. Saaidi, “Hamilton-Jacobi formalism for in?ation with nonminimal derivative coupling” ( Journal of Cosmology and Astroparticle Physics 1610 (2016) no.10, 021) arXiv:1603.03883[gr-qc]. 3. S. W. Rabeie, H. Sheikhahmadi, Kh. Saaidi, A. Aghamohammadi, “Interacting cosmology in light of SNeIa, CMB, BAO and OHD observational data sets” Eur. Phys. J. C (2016) 76:66 arXiv:1502.05952 [astro-ph.CO]. 4. H. Sheikhahmadi, A. Aghamohammadi, Kh. Saaidi, “The e?ect of de Sitter like background on increas- ing the zero point budget of dark energy” (Advance in High Energy physics, 2016) arXiv:1407.0125[gr- qc]. 5. H. Sheikhahmadi, A. Aghamohammadi, Kh. Saaidi,. “Non-commutative and commutative vacua ef- fects in a scalar torsion scenario” Physics Letters B 749, 231, 2015, arXiv:1506.08416[gr-qc]. 6. Kh. Saaidi, A. Mohammadi, H. Sheikhahmadi, “? parameter and solar system constraints in chameleon Brans Dicke theory ”, Physical Review D, 83 (2011) 5, arXiv:1201.0372 [physics.gen-ph]. 7. Kh. Saaidi, A. Mohammadi, T. Golanbari, H. Sheikhahmadi, and B. Ratra, “Quark-hadron phase transi- tion in a chameleon Brans-Dicke model of brane gravity ”, Phys. Rev. D 86, 045007 (2012), arXiv:1201.0372 [physics.gen-ph]. 8. H. Sheikhahmadi, S. Ghorbani and Kh. Saaidi, “Non-local scalar ?elds in?ationary mechanism in light of Planck 2013”, Astrophys. Space Sci. 357, No. 115 (2015) arXiv:1502.05166[qr-qc]. 9. Z. Ossoulian, T. Golanbari, H. Sheikhahmadi, Kh. Saaidi, “Stability of a noncanonical scalar ?eld model during cosmological date”, Advances in High Energy Physics 2016 (2016) 10 arXiv:arXiv:1512.05571[gr- qc]. 10. Kh. Saaidi, H. Sheikhahmadi, T. Golanbari, and S. W. Rabiei “On the holographic dark energy in chameleon scalar-tensor cosmology” , Astrophys. Space Sci. 348, 233 (2013), arXiv:1404.2139[gr-qc]. 11. A. Aghamohammadi, Kh. Saaidi, A. Mohammadi, H. Sheikhahmadi, T. Golanbari, S. W. Rabeie “E?ect of an external interaction mechanism in solving agegraphic dark energy problems” , Astrophys Space Sci 345, 17 (2013), arXiv:1404.2139[gr-qc]. 12. Kh. Saaidi, H. Sheikhahmadi, A. Mohammadi, “Interacting new agegraphic dark energy in a cyclic uni- verse ”, Astrophys Space Sci 338, 355 (2012), arXiv:1201.0275[gr-qc]. 13. Kh. Saaidi, H. Sheikhahmadi, J. Afzali, “ Chameleon Mechanism with a New Potential ”, Astrophys Space Sci 333, 501 (2011) arXiv:1011.0075[physics.gen-ph]. 14. Kh. Saaidi, A. Vajdi, S.W. Rabiei, A. Aghamohammadi, H. Sheikhahmadi “Strong and weak gravitational ?eld in R +µ4/R gravity” Astrophys Space Sci 337, 739 (2012), arXiv:1001.4157[gr-qc].

Present Research Project at IPM

Schwinger-Keldysh formalism to investigate spectroscopy of primordial interactions

Related Papers

1.	H. Sheikhahmadi, S. Soroushfar, S.N. . Sajadi and T. Harko Astrophysical and electromagnetic emissivity properties of black holes surrounded by a quintessence type exotic fluid in the scalarâ??vectorâ??tensor modified gravity Eur. Phys. J. C 814 (2023),   [abstract] Code: IPM/A-2023/17

2.	H. Firouzjahi and H. Sheikhahmadi Vacuum Zero Point Energy and its Statistical Correlations in dS Background Phys. Rev. D 108 (2023),   [abstract] Code: IPM/A-2023/05

3.	T. Harko, K. Asadi, H. Moshafi and H. Sheikhahmadi Observational constraints on the interacting dark energy - dark matter (IDM) cosmological models Physics of the Dark Universe 38 (2022),   [abstract] Code: IPM/A-2022/40

4.	H. Sheikhahmadi On the origin of the holographic universe Mod. Phys. Lett. A 37 (2022),   [abstract] Code: IPM/A-2022/35

5.	H. Sheikhahmadi Schwarzschild black hole perturbed by a force-free magnetic field Found. Phys. (2022),   [abstract] Code: IPM/A-2022/31

6.	S. Soroushfar, R. Saffari, A. Abebe and H. Sheikhahmadi Thermodynamic geometry of static and rotating regular black holes in conformal massive gravity Eur. Phys. J. plus (2021),   [abstract] Code: IPM/A-2021/34

7.	T. Harko and H. Sheikhahmadi Warm inflation with non-comoving scalar field and radiation fluid Eur. Phys. J. C (2021),   [abstract] Code: IPM/A-2020/35

8.	H. Sheikhahmadi, M. Faizal, A. Aghamohammadi, S. Soroushfar and S. Bahamonde Inflation in String Field Theory Nucl. Phys. B 961 (2020),   [abstract] Code: IPM/A-2020/39

9.	T. Harko and H. Sheikhahmadi Irreversible thermodynamical description of warm inflationary cosmological models Physics of the Dark Universe 28 (2020),   [abstract] Code: IPM/A-2020/28

10.	A. Mohammadi, T. Golanbari, H. Sheikhahmadi, K. Sayar, L. Akhtari, M. A. . Rasheed and Kh. Saaidi Warm Tachyon Inflation and Swampland Criteria Chinese Physics C 44 (2020),   [abstract] Code: IPM/A-2020/23

11.	T. Harko and H. Sheikhahmadi Irreversible thermodynamical description of warm inflationary cosmological models Physics of the Dark Universe 28 (2020),   [abstract] Code: IPM/A-2019/50

12.	Z. Ghadiri, A . Refaei, A. Aghamohammadi and H. Sheikhahmadi Constraints on warm power-law inflation in light of Planck results Mod. Phys. Lett. A 35 (2019),   [abstract] Code: IPM/A-2019/52

13.	H. Sheikhahmadi Schwinger-Keldysh mechanism in extended quasi single field inflation Eur. Phys. J. C 451 (2019),   [abstract] Code: IPM/A-2019/49

14.	A. Mohammadi, Kh. Saaidi and H. Sheikhahmadi Constant-roll approach to non-canonical inflation Phys. Rev. D 100 (2019),   [abstract] Code: IPM/A-2019/47

15.	M. Naderi, A. Aghamohammadi, A. Refaei and H. Sheikhahmadi Intermediate inflation with non-canonical scalar field in the low anisotropy Universe Mod. Phys. Lett. A 34 (2019),   [abstract] Code: IPM/A-2019/46

16.	H. Sheikhahmadi, A. Mohammadi, A. Aghamohammadi, T. Harko, R. Herrera, Ch. Corda, A. Abebe and Kh. Saaidi Constraining chameleon field driven warm inflation with Planck 2018 data Eur. Phys. J. C (2019),   [abstract] Code: IPM/A-2019/44