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Scientists of the Faculty of Physics and Technology at 91��ý Kazakh National University are taking a new step in exploring one of the most complex and fascinating subjects of modern astrophysics — black holes. Today, understanding the nature of black holes is of tremendous importance not only for fundamental science, but also for expanding humanity’s knowledge of the structure of the Universe. In this direction, researchers at KazNU are implementing a large-scale project entitled “Investigating Observable Signatures of Dilaton Black Holes.” The project focuses on studying the unique properties of dilaton black holes — objects predicted in alternative theories of gravity that differ from the standard black hole models.

One of the most remarkable achievements in astrophysics in recent years has been the first imaging of the shadows of the black holes M87* and Sgr A* by the Event Horizon Telescope Collaboration. This breakthrough not only confirmed the existence of black holes, but also opened new opportunities for studying the structure of spacetime surrounding them. Although current observations are generally consistent with Einstein’s General Theory of Relativity, certain data — particularly the orbital characteristics of the G2 object near the center of our Galaxy — suggest that alternative models beyond the classical Kerr black hole may also be relevant. In this context, dilaton black holes are of special interest because they arise as solutions to Einstein’s equations supplemented by additional scalar fields. Investigating their optical and dynamical properties provides an important way to test modern gravitational theories.

The primary objective of the project is the analytical and numerical investigation of accretion disks, quasiperiodic oscillations, and black hole shadows in the spacetime of dilaton black holes. The study aims to identify unique signatures that distinguish dilaton black holes from standard Schwarzschild or Kerr black holes. Researchers plan to analyze orbital parameters of particles within accretion disks, including angular velocity, angular momentum, energy, and effective potential. Using the Novikov–Thorne–Page model, the team will investigate the stability of circular orbits, the radius of the innermost stable circular orbit, radiation flux, and disk luminosity. These studies will provide deeper insight into how physical parameters influence the properties of accretion structures surrounding black holes.

Another important direction of the project is the investigation of fundamental epicyclic frequencies of particle motion in the metric of dilaton black holes. Based on the Stella–Vietri relativistic precession model, researchers will compare theoretical predictions with observed quasiperiodic oscillation (QPO) data. This approach will allow scientists to determine key black hole parameters, including mass and charge, for real astrophysical objects such as GRO J1655-40, XTE J1550-564, and GRS 1915+105. In addition, the project includes solving geodesic equations for photons, calculating photon sphere radii, and analyzing black hole shadow intensities. The brightness of photon rings and shadows of dilaton black holes under spherical accretion conditions will also be modeled.

To address these highly sophisticated problems, the KazNU research team employs advanced computational methods and software tools, including Python, Mathematica, and Maple. Special attention is devoted to modeling black hole shadows and photon rings using backward ray-tracing techniques optimized through GPU acceleration. This approach enables highly accurate calculations of photon trajectories in curved spacetime. The obtained results are expected to be compared with EHT observational data for Sgr A* and M87*, allowing researchers to place constraints on the parameters of dilaton black holes.

The scientific novelty of the project lies in the comprehensive investigation of optical properties of accretion disks and quasiperiodic oscillations around dilaton black holes. These studies may play a crucial role in distinguishing between different classes of black holes. The project is interdisciplinary in nature, combining general relativity, astrophysics, mathematical physics, and numerical computation. Such research not only advances theoretical understanding, but also strengthens international scientific cooperation and collaboration with leading research centers worldwide.

The project is also highly significant for enhancing the scientific and technological potential of Kazakhstan. Particular attention is given to training highly qualified specialists, including PhD students and postdoctoral researchers, thereby strengthening the country’s human resource capacity in astrophysics. The research findings are expected to be published in leading international scientific journals, increasing the global competitiveness of Kazakhstani science. Although the project is fundamentally theoretical, it also creates a foundation for future developments in astrophysical data analysis and advanced space technologies.

The project is scheduled for implementation during 2025–2027 and is supported by more than 118 million tenge in government grant funding. These resources will be used for advanced computational infrastructure, participation in international conferences, and conducting research at a high scientific level. By the end of the project, the technological readiness level is expected to advance from fundamental research toward the development of new astronomical methods and approaches.

In conclusion, this initiative by scientists of 91��ý Kazakh National University represents an important step toward uncovering the mysteries of black holes, exploring new aspects of gravity, and strengthening the position of Kazakhstani science on the global stage. Research into the shadows and dynamics of dilaton black holes has the potential not only to transform our understanding of the Universe, but also to pave the way for future astrophysical discoveries.