Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity
In this study, we investigate the properties of a thin accretion disk around a static spherically symmetric black hole in 4D Einstein–Gauss–Bonnet gravity, with an additional coupling constant, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline&q...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article |
| Language: | English |
| Published: |
MDPI AG
2025-01-01
|
| Series: | Universe |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2218-1997/11/2/38 |
| Tags: |
Add Tag
No Tags, Be the first to tag this record!
|
| _version_ | 1850238707998654464 |
|---|---|
| author | Odilbek Kholmuminov Bakhtiyor Narzilloev Bobomurat Ahmedov |
| author_facet | Odilbek Kholmuminov Bakhtiyor Narzilloev Bobomurat Ahmedov |
| author_sort | Odilbek Kholmuminov |
| collection | DOAJ |
| description | In this study, we investigate the properties of a thin accretion disk around a static spherically symmetric black hole in 4D Einstein–Gauss–Bonnet gravity, with an additional coupling constant, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>, appearing in the spacetime metric. Using the Novikov–Thorne accretion disk model, we examine the thermal properties of the disk, finding that increasing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> reduces the energy, angular momentum, and effective potential of a test particle orbiting the black hole. We demonstrate that <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> can mimic the spin of a Kerr black hole in general relativity up to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>a</mi><mo>≃</mo></mrow></semantics></math></inline-formula> 0.23 M for the maximum value of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>. Our analysis of the thermal radiation flux shows that larger <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> values increase the flux and shift its maximum towards the central black hole, while far from the black hole, the solution recovers the Schwarzschild limit. The impact of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> on the radiative efficiency of the disk is weak but can slightly alter it. Assuming black-body radiation, we observe that the disk’s temperature peaks near its inner edge and is higher for larger <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> values. Lastly, the electromagnetic spectra reveal that the disk’s luminosity is lower in Einstein–Gauss–Bonnet gravity compared to general relativity, with the peak luminosity shifting toward higher frequencies, corresponding to the soft X-ray band as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> increases. |
| format | Article |
| id | doaj-art-a6d475e940cf47ada9f332126d7e295d |
| institution | OA Journals |
| issn | 2218-1997 |
| language | English |
| publishDate | 2025-01-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Universe |
| spelling | doaj-art-a6d475e940cf47ada9f332126d7e295d2025-08-20T02:01:24ZengMDPI AGUniverse2218-19972025-01-011123810.3390/universe11020038Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet GravityOdilbek Kholmuminov0Bakhtiyor Narzilloev1Bobomurat Ahmedov2Institute of Fundamental and Applied Research, National Research University TIIAME, Kori Niyoziy 39, Tashkent 100000, UzbekistanDepartment of Physics, New Uzbekistan University, Movarounnahr Str. 1, Tashkent 100000, UzbekistanInstitute of Fundamental and Applied Research, National Research University TIIAME, Kori Niyoziy 39, Tashkent 100000, UzbekistanIn this study, we investigate the properties of a thin accretion disk around a static spherically symmetric black hole in 4D Einstein–Gauss–Bonnet gravity, with an additional coupling constant, <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>, appearing in the spacetime metric. Using the Novikov–Thorne accretion disk model, we examine the thermal properties of the disk, finding that increasing <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> reduces the energy, angular momentum, and effective potential of a test particle orbiting the black hole. We demonstrate that <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> can mimic the spin of a Kerr black hole in general relativity up to <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><mi>a</mi><mo>≃</mo></mrow></semantics></math></inline-formula> 0.23 M for the maximum value of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula>. Our analysis of the thermal radiation flux shows that larger <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> values increase the flux and shift its maximum towards the central black hole, while far from the black hole, the solution recovers the Schwarzschild limit. The impact of <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> on the radiative efficiency of the disk is weak but can slightly alter it. Assuming black-body radiation, we observe that the disk’s temperature peaks near its inner edge and is higher for larger <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> values. Lastly, the electromagnetic spectra reveal that the disk’s luminosity is lower in Einstein–Gauss–Bonnet gravity compared to general relativity, with the peak luminosity shifting toward higher frequencies, corresponding to the soft X-ray band as <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mi>α</mi></semantics></math></inline-formula> increases.https://www.mdpi.com/2218-1997/11/2/38black holeaccretion diskgeneral relativityEinstein–Gauss–Bonnet gravity |
| spellingShingle | Odilbek Kholmuminov Bakhtiyor Narzilloev Bobomurat Ahmedov Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity Universe black hole accretion disk general relativity Einstein–Gauss–Bonnet gravity |
| title | Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity |
| title_full | Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity |
| title_fullStr | Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity |
| title_full_unstemmed | Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity |
| title_short | Thermal Profile of Accretion Disk Around Black Hole in 4D Einstein–Gauss–Bonnet Gravity |
| title_sort | thermal profile of accretion disk around black hole in 4d einstein gauss bonnet gravity |
| topic | black hole accretion disk general relativity Einstein–Gauss–Bonnet gravity |
| url | https://www.mdpi.com/2218-1997/11/2/38 |
| work_keys_str_mv | AT odilbekkholmuminov thermalprofileofaccretiondiskaroundblackholein4deinsteingaussbonnetgravity AT bakhtiyornarzilloev thermalprofileofaccretiondiskaroundblackholein4deinsteingaussbonnetgravity AT bobomuratahmedov thermalprofileofaccretiondiskaroundblackholein4deinsteingaussbonnetgravity |