https://doi.org/10.1140/epjc/s10052-025-14899-z
Regular Article - Theoretical Physics
Vacuum and plasma magnetosphere around rotating magnetized neutron stars in Bocharova–Bronnikov–Melnikov–Bekenstein geometry
1
Samarkand State University, University blv.15, 140104, Samarkand, Uzbekistan
2
Mathematics Department, College of Computing and Mathematics, King Fahd University of Petroleum and Minerals, P.O. Box 31261, 31262, Dhahran, Saudi Arabia
3
School of Physics, Harbin Institute of Technology, 150001, Harbin, People’s Republic of China
4
Institute for Advanced Studies, New Uzbekistan University, Movarounnahr str. 1, 100000, Tashkent, Uzbekistan
5
National University of Uzbekistan, 100174, Tashkent, Uzbekistan
6
University of Tashkent for Applied Sciences, Gavhar Str. 1, 700127, Tashkent, Uzbekistan
7
Urgench State University, Kh. Alimjan str. 14, 221100, Urgench, Uzbekistan
8
Tashkent State Technical University, 100095, Tashkent, Uzbekistan
a
This email address is being protected from spambots. You need JavaScript enabled to view it.
Received:
11
August
2025
Accepted:
6
October
2025
Published online:
24
November
2025
Abstract
In this work, we explore the vacuum and plasma magnetosphere of a slowly rotating, magnetized neutron star in a conformally coupled scalar field, so-called Bocharova–Bronnikov-Melnikov–Bekenstein (BBMB) geometry. Starting from the vacuum solutions to Maxwell’s equations in a curved spacetime, we derive modified magnetic and electric field structures in the BBMB geometry. We then investigate the behavior of the Goldreich–Julian (GJ) charge density, accelerating electric fields parallel to magnetic field lines, pair production thresholds, and the rate of energy loss through dipolar radiation in the magnetized star. The coupled scalar field significantly enhances magnetic field strength, charge separation, and parallel acceleration, as well as particle acceleration. We also study the deathline conditions that are responsible for secondary pair formation in the BBMB geometry. All results are compared with the general relativistic (GR) limit. As a result, deathline in the 
diagram is located above in the spacetime compared with GR frame, implying extended pulsar activity compared to GR. Radiative luminosities from the magnetodipolar radiation process are also increased compared to GR predictions. These findings suggest that BBMB gravity could play a crucial role in shaping the high-energy phenomena of neutron stars and offer new avenues for testing gravity in strong-field regimes.
© The Author(s) 2025
Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article’s Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article’s Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/.
Funded by SCOAP3.
