Dr. Tiberiu Harko
Associated Researcher
2001, Hong Kong University, P.R. China
general relativity and quantum cosmology, astro-particle physics, mathematical physics
modified theories of gravity, cosmology, high energy astrophysics, mathematical physics


My research interests include General Relativity, Astrophysics, Cosmology, Modeling of compact stars, Dark energy and Modified theory of gravity. Currently, I am working mainly on modified theories of gravity, including the study of several extensions of General Relativity (theories with geometry-matter coupling, Hybrid Metric Palatini Gravity, and Finslerian Relativity, respectively). Together with my collaborators we have obtained several well-behaved exact cosmological solutions of Einstein field equations that could describe both early and late evolution of the Universe. Most of my present work concentrates on Dark Energy and extensions of gravitational theories, including obtaining and investigating more general classes of cosmological solutions, mainly focusing on interacting dark energy models, scalar field models of dark energy (quintessence), and dark energy in the Hybrid Metric-Palatini gravity theory. I am also working on constraining dark energy models, both at background and perturbative levels, from the combined analysis of latest observational data coming from different astronomical sources, satisfying all conditions to achieve viable cosmological expansion scenarios.

On the other hand, my main aim is to address the issue of the accelerated expansion of the Universe, whose resolution is so important for theoretical cosmology, looking beyond the standard theory of gravity. One of the important reason for the modification of Einstein's general relativity is to understand how one may differentiate modified theories of gravity from standard dark energy models, including the LambdaCDM paradigm. There exist many constraints that have to be satisfied in order for a model to be considered viable, at least to some extent. In this context it is important to have a broad and general framework to interpret and analyze the data, which can provide new observational bounds on the model parameters from the latest observations. I am trying to explore a plethora of viable modified gravity models, which will be tested against large-scale structure and lensing, astrophysical and laboratory measurements, to restrict the range of allowed modified gravity models, as well as their free parameters.


  1. T. Harko and H. Sheikhahmadi, Warm inflation with non-comoving scalar field and radiation fluid, Eur. Phys. J. C 81, 165 (2021).
  2. J.-Z. Yang, S. Shahidi, T. Harko, S.-D. Liang, Black hole solutions in modified gravity induced by quantum metric fluctuations, Physics of the Dark Universe 31, 100756 (2021).
  3. M. Craciun and T. Harko, Testing Bose-Einstein Condensate dark matter models with the SPARC galactic rotation curves data, European Physical Journal C 80, 735 (2020.
  4. T. Harko, F. S. N. Lobo, H. M. R. da Silva, Cosmic stringlike objects in hybrid metric-Palatini gravity, Phys. Rev. D 101, 124050 (2020).
  5. T. Harko and H. Sheikhahmadi, Irreversible thermodynamical description of warm inflationary cosmological models, Physics of the Dark Universe 28, 100521 (2020) .
Funding Agencies: