Research areas: Gravitation, Black holes, Wormholes, Cosmology, Gravitational Lensing, Geodesics, Shadow , Hawking Radiation, Greybody factor, Quasinormal modes, Complexity.

Dr. Övgün's research is focused on understanding and constraining modified gravity theories using various properties of black holes and cosmological evolution. He has contributed to various analysis methods, which are now amongst the most widely used ones for calculating the Hawking radiation, gravitational lensing, and shadow cast of black holes. He has been studying various aspects of general relativity in relation to black hole properties, wormholes, compact stars, Hawking radiation, and cosmological inflation. Dr. Övgün is among World’s Top 2% Scientists in the Stanford University 2020 & 2021 Releases Lists.

He try to address a number of interesting questions in physics, such as:

-Is it possible that the Big Bang could be replaced with a wormhole at the beginning of time?

-Is it possible to create a traversable wormhole?

-How can quantum effects be included in black hole/wormhole thermodynamics?

-What happens at the edge of a Black Hole or inside a Black hole?

-Could Our Universe Be A Hologram? or How Many Dimensions In The Holographic Universe?

-Why is the universe expanding at an accelerating rate?

-How are Brain Cells Like Little Universes? so on...

His research is centered around the problem of Quantum Gravity, but spans a large number of topics related to it, in mathematical/theoretical physics, foundations and philosophy of physics, up to philosophy of science more generally.

A main goal is to extract from quantum gravity an effective description of our universe that could provide answers to outstanding open issues in fundamental cosmology, concerning the very early universe and the dark energy problem, but also in the context of black hole physics.

**Research Topics for M.Sc. and Ph.D Students ****- COSMOLOGY:** Cosmological models with Nonlinear electrodynamics, Cosmological singularities, Inflation, Acceleration of Universe.**-WORMHOLES:** Stability of Thin-shell Wormholes and Lorentzian Wormholes (WHs).**-GRAVITATIONAL LENSING & SHADOW CAST: ** Weak/Strong Gravitational Lensing, Light Deflection with Topological Defects and Gauss-Bonnet Theorem, Shadow of the Black holes/ Wormholes, Thin-accretion disk.**-COMPACT STARS & GRAVASTARS****-WAVE PROPERTIES OF BHs & WHs:** Hawking Radiation, Quasinormal Modes of Black Holes, Greybody factors, Quantum Singularities.**-PARTICLE PROPERTIES OF BHs & WHs:** Geodesics and BSW effect of BHs/WHs, Particle Acceleration by BHs/Whs**-BLACK HOLE CHEMISTRY: **Thermodynamics with Lambda, P-V Criticality, Phase Transitions, Super-entropic BH, Van der Waals fluids, Holographic Thermodynamics **-ENTANGLEMENT & COMPLEXITY:** Quantum complexity inside black holes; Action Growth Rates**-MODIFIED GRAVITY THEORIES:** Bumblebee model of gravity, Gauss-Bonnet gravity, f(R) gravity et.c

SUPERVISORSHIPS

• PhD Supervisor: YASHMITHA KUMARAN

Weak Deflection Angle via Gauss-Bonnet Theorem, 2018-Now.

• MSc Supervisor: FLORA BABAYEVA

Shadow Cast of The Schwarzschild-like Black Holes, 2020-2022.

• MSc Supervisor: HAMZA SABER ZEBARI

Newtonian Cosmology, 2018-2020.

• MSc Supervisor: GABRIEL WIRDZELII JOSEPH

Cosmology with Varying Physical Constants, 2018-2020.

• MSc Co-Supervisor: HUSEYIN KARYAL

Geodesics of Black Holes in Bumblebee Gravity Theory, 2018-2020.

•Msc Co-Supervisor: ILIM IRFAN CIMDIKER (SABANCI UNIVERSITY-TURKEY)

Black Hole Shadow in Symmergent Gravity, PHYSICS OF DARK UNIVERSE

2021. (Supervisor: Prof.Dr.Durmus Ali Demir)

• BSc Co-Supervisor: CEREN H. BAYRAKTAR (IYTE-TURKEY)

Thermodynamics of regular black holes with cosmic strings, European Physical

Journal - Plus 2018. (Supervisor: Prof.Dr.Durmus Ali Demir)

• BSc Co-Supervisor: MERT OKYAY (MIAMI UNI.-USA)

Nonlinear electrodynamics effects on the black hole shadow, deflection angle, quasinormal modes and greybody factors, Journal of Cosmology and Astroparticle

Physics 2022.