Interview with Prof. Dr. Tiberiu Harko—Winner of the Symmetry Best Paper Award

We are pleased to announce that Prof. Dr. Tiberiu Harko’s paper “Jacobi and Lyapunov Stability Analysis of Circular Geodesics around a Spherically Symmetric Dilaton Black Hole” has won the Symmetry 2023 Best Paper Award, as it is one of the exceptional articles published in Symmetry (ISSN: 2073-8994). As winners of this award, Prof. Harko and coauthors Prof. Cristina and Paul Blaga will receive CHF 400, a certificate, and a free voucher for article processing fees valid for one year.

The following is a short interview with the winner, Prof. Dr. Tiberiu Harko:

1. Congratulations on winning the Symmetry 2023 Best Paper Award! Could you please briefly introduce yourself?
I begin by expressing my gratitude to the editorial office for inviting me to participate in this interview. I earned my bachelor’s degree in physics from Babeș-Bolyai University. Later, I pursued my doctoral studies at the University of Hong Kong, where I was awarded my PhD in 2001. I spent around 15 years in the Department of Physics of the University of Hong Kong before moving to Guangzhou, China, where I joined the Yat Sen School of the Sun Yat-sen University in 2013 as a Full Professor. I have also held academic positions at the University College London (UCL). Due to the travel restrictions during COVID-19 in 2019 and 2020, I was unable to return to China and have since remained in my hometown in Romania.

2. Could you give a brief overview of the main content of your award-winning paper?
In this collaborative paper with two colleagues from the Department of Mathematics, we analyzed the stability of circular geodesics around a charged dilaton black hole (GMGHS solution) using both Lyapunov and Jacobi stability methods. The Jacobi approach, based on Kosambi–Cartan–Chern (KCC) theory, provided a geometric framework to examine particle trajectories via nonlinear connections and curvature deviation tensors. Our key finding was the equivalence between Lyapunov and Jacobi stability criteria for circular orbits, with stability determined by the sign of the second derivative of the effective potential. This work demonstrates the applicability of advanced geometric stability methods in black hole physics, particularly for systems derived from string theory.

3. Can you introduce your current research focus and the main research areas of your team?
My current research focuses on the modification of gravitational theories. Together with my colleagues and students, we are actively exploring alternative theoretical frameworks to explain recent cosmological observations. Specifically, we investigate the possibility that this observational data may provide evidence for deviations from the classical description of gravity as formulated in Einstein’s General Relativity. Our work seeks to develop models that could potentially offer viable alternatives to the standard ΛCDM (Lambda Cold Dark Matter) cosmological paradigm.

4. Could you describe some challenges and breakthroughs in your research field?
In my field, we face the same challenges as the broader scientific community—particularly in explaining many recent observations that are both important and intriguing. These findings suggest we may need to fundamentally rethink our current cosmological models and even the foundational principles of gravitational theory. As for potential breakthroughs, I have to admit it's difficult to predict clear outcomes. Research in cosmology and gravity moves incredibly fast, with new theories constantly emerging to address observational puzzles. Because of this, we can't yet say which approach will ultimately hold up—or when a major discovery might happen.

5. What factors attracted you to submit your paper to Symmetry? How was your submission experience?
I had been aware of Symmetry for some time before deciding to submit my paper. I appreciated the journal’s strong publishing history, its broad coverage of multiple fields, and its focus on symmetry—a fundamental concept across physics, chemistry, mathematics, and other areas. These factors made the journal particularly appealing to me. Later, I received an invitation to submit my work. I found the submission system straightforward to use, the editors very helpful, and the review reports constructive. The reviewers pointed out two specific issues, which my co-authors and I successfully addressed in our revisions.

6. In your opinion, which research topics will attract widespread attention in the academic community in the coming years?
I can speak primarily from my area of expertise. In my view, cosmology is likely to remain a dominant field for many years, given that it currently receives a substantial influx of observational data. As one of the few branches of physics with such extensive observational input, I expect cosmology to continue being highly active and influential well into the future. While I acknowledge the potential for breakthroughs and discoveries in other areas of physics, I believe that cosmology will continue to be a prominent and dynamic field for several decades.

7. What advice would you give to young researchers who aspire to produce high-impact research results?
My advice to young researchers who aspire to produce high-impact research results is to pursue topics they are truly passionate about. I believe this is essential for achieving meaningful outcomes. Identifying your genuine interests within the scientific field, combined with dedicated effort, is the key to producing significant and impactful work.

8. As the recipient of this award, could you share your feelings and whom you would like to thank?
I was truly surprised and deeply grateful to learn that I had received this award, which I consider a tremendous honor. I would also like to express my heartfelt thanks to my co-authors, Cristina and Paul Blaga—they deserve immense credit for this work and played an essential role in the success of our paper.

9. Symmetry is an open access journal. How do you think open access impacts readers and authors?
I consider open access publishing to be somewhat controversial at present. Many excellent researchers may lack the financial resources to support open access publication fees. However, based on my experience with Symmetry and other MDPI journals, I’ve noted that there are opportunities to publish certain papers free of charge (Editor's note: For every manuscript reviewed in MDPI journals, the reviewer may receive a discount voucher code entitling them to a reduction in the article processing charge (APC) of a future submission to any MDPI journal). I view this policy positively, as it helps support scholars and specific research projects. Additionally, I’d highlight a key advantage of open access: making scientific papers freely accessible to the entire research community. Overall, I believe that open access is a valuable approach that promotes broader dissemination and democratization of scientific knowledge.

More information about journal awards can be found at the following link: https://www.mdpi.com/journal/symmetry/awards.