Photon Spheres near Dilatonic Dyon-Like Black Holes in a Model with Two Abelian Gauge Fields and Two Scalar Fields
Ivashchuk V.D. Malybayev A.N. Nurbakova G.S. Takey G.
December 2023Pleiades Publishing
Gravitation and Cosmology
2023#29Issue 4411 - 418 pp.
Abstract: Dilatonic dyon-like black hole solutions with two (color) charges Q1 and Q2 (electric and magnetic ones) are considered in a gravitational 4D model with two scalar fields and two 2-forms. Two-dimensional dilatonic coupling vectors (Formula presented.), i=1,2, determining the model, obey the relation (Formula presented.). Circular null geodesics in the field of such black holes are explored. The master equation for the photon sphere radius R is derived. A conjecture is suggested on the existence and uniqueness of the solution to the master equation with (Formula presneted.), where Rg is the horizon radius. This conjecture is varified for certain special cases, e.g., for a charge symmetric configuration: (Formula presneted.). In this charge symmetric case, we present a relation for the spectrum of quasinormal modes of a test massless scalar field in the eikonal approximation, and an example of circular orbits of a massive particle.
Text of the article Перейти на текст статьи
Peoples’ Friendship University of Russia (RUDN University), ul. Miklukho-Maklaya 6, Moscow, 117198, Russian Federation
Center for Gravitation and Fundamental Metrology, VNIIMS, ul. Ozyornaya 46, Moscow, 119361, Russian Federation
Al-Farabi Kazakh National University, Al-Farabi avenue, 71, Almaty, 050040, Kazakhstan
Peoples’ Friendship University of Russia (RUDN University)
Center for Gravitation and Fundamental Metrology
Al-Farabi Kazakh National University
10 лет помогаем публиковать статьи Международный издатель
Книга Публикация научной статьи Волощук 2026 Book Publication of a scientific article 2026