theoretical physics

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theoretical physics

Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma

Yusra A. A. Hager, Mahmood A. H. Khaled, Mohamed A. Shukri

2023-12-21

DOI: 10.59628/jast.v1i4.583

Abstract

A linear analysis was performed to investigate the basic properties of waves propagating in different directions in magnetized quantam plasma consisting of classical warm ions and relativistic degenerate electrons. We employ a quantum magnetohydrodynamic approach considering quantum corrections, spin effects in addition to relativity, and a polytropic index to obtain a generalized dispersion relation of the regarded plasma system. The considered system supports three types of magnetohydrodynamic waves: Alfven, fast, and slow magnetosonic waves. The obtained modified Alfven and magnetosonic dispersion relations are affected by the obliqueness factor, spin magnetization, and plasma beta .The fast and slow modes were also altered owing to the Bohm potential and relativistic degenerate pressure impacts. Examination of the influences of these parameters revealed a significant modification of the phase velocity features of the magnetohydrodynamic waves. The results obtained may be applicable to relativistic magnetized quantum plasmas in astrophysical environments.

Keywords

Magnetohydrodynamic waves Relativistic degenerate plasma Alfven waves Magnetosonic waves QuantamMagnetohydrodynamic model
How to Cite This Article
Yusra A. A. Hager, Mahmood A. H. Khaled, Mohamed A. Shukri (2023). Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma. Sana'a University Journal of Applied Sciences and Technology. DOI: https://doi.org/10.59628/jast.v1i4.583

Yusra A. A. Hager, Mahmood A. H. Khaled, Mohamed A. Shukri . “Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma.” Sana'a University Journal of Applied Sciences and Technology, 2023, https://doi.org/10.59628/jast.v1i4.583. Accessed 20 Sep. 2026.

Yusra A. A. Hager, Mahmood A. H. Khaled, Mohamed A. Shukri . 2023. “Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma.” Sana'a University Journal of Applied Sciences and Technology DOI: https://doi.org/10.59628/jast.v1i4.583

Yusra A. A. Hager, Mahmood A. H. Khaled, Mohamed A. Shukri (2023) ‘Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma’, Sana'a University Journal of Applied Sciences and Technology. doi: 10.59628/jast.v1i4.583

@article{jast2023_art583, author = {Yusra A. A. Hager, Mahmood A. H. Khaled, Mohamed A. Shukri }, title = {Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma}, journal = {Sana'a University Journal of Applied Sciences and Technology}, year = {2023}, month = {December}, doi = {10.59628/jast.v1i4.583}, url = {https://doi.org/10.59628/jast.v1i4.583},}

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Characteristics of magnetohydrodynamic waves propagating in a magnetized relativistic degenerate plasma

Yusra A. A. Hager Corresponding hager22013@gmail.com

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On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index

Obidah Ali A. Alshrafi, Mohammed S. Qusailah, Mohamed K. Al-Motawake, Abdu A. Alkelly

1315-1322

2025-12-28

DOI: 10.59628/jast.v3i6.2041

Abstract

This study explores a novel conceptual link between the dynamics of Lovelock gravity and the topological structure of spacetime. We introduce a theoretical framework in which the gravitational action—particularly in Lovelock theories is connected to the sum of topological indices of a vector field defined on the spacetime manifold, consistent with the Poincaré-Hopf theorem. Specifically, we propose that the value of the pth-order Lovelock action, recognized as a topological invariant in 2p dimensions, corresponds to the sum of indices associated with topological defects such as black hole horizons or spacetime singularities. Although the explicit construction of this vector field is left for future work, we present a foundational formulation and demonstrate its implications using the Schwarzschild solution, where the index sum reproduces the known Euler characteristic. This approach offers a topologically grounded perspective on gravitational dynamics and suggests new directions for understanding the geometric and physical properties of spacetime.

Keywords

Lovelock gravity spacetime Poincaré-Hopf theorem black hole horizon spacetime singularities Schwarzschild solution Euler characteristic
How to Cite This Article
Obidah Ali A. Alshrafi, Mohammed S. Qusailah, Mohamed K. Al-Motawake, Abdu A. Alkelly (2025). On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index. Sana'a University Journal of Applied Sciences and Technology, 1315-1322. DOI: https://doi.org/10.59628/jast.v3i6.2041

Obidah Ali A. Alshrafi, Mohammed S. Qusailah, Mohamed K. Al-Motawake, Abdu A. Alkelly . “On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index.” Sana'a University Journal of Applied Sciences and Technology, 2025, pp. 1315-1322. https://doi.org/10.59628/jast.v3i6.2041. Accessed 20 Sep. 2026.

Obidah Ali A. Alshrafi, Mohammed S. Qusailah, Mohamed K. Al-Motawake, Abdu A. Alkelly . 2025. “On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index.” Sana'a University Journal of Applied Sciences and Technology : 1315-1322. DOI: https://doi.org/10.59628/jast.v3i6.2041

Obidah Ali A. Alshrafi, Mohammed S. Qusailah, Mohamed K. Al-Motawake, Abdu A. Alkelly (2025) ‘On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index’, Sana'a University Journal of Applied Sciences and Technology, pp. 1315-1322. doi: 10.59628/jast.v3i6.2041

@article{jast2025_art2041, author = {Obidah Ali A. Alshrafi, Mohammed S. Qusailah, Mohamed K. Al-Motawake, Abdu A. Alkelly }, title = {On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index}, journal = {Sana'a University Journal of Applied Sciences and Technology}, year = {2025}, month = {December}, pages = {1315-1322}, doi = {10.59628/jast.v3i6.2041}, url = {https://doi.org/10.59628/jast.v3i6.2041},}

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On the Connection Between Lovelock Gravity and the Poincaré-Hopf Index

Obidah Ali A. Alshrafi Corresponding obidah.alsharfi@su.edu.ye

Abdu A. Alkelly obidah.alsharfi@su.edu.ye

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