Ion-acoustic solitons in a relativistic Fermi plasma at finite temperature

Abstract

The theory of ion-acoustic solitons in nonrelativistic fully degenerate plasmas and nonrelativistic and ultra-relativistic degenerate plasmas at low temperatures is known. We consider a multi-component relativistic degenerate electron-positron-ion plasma at finite temperatures. Specifically, we focus on the intermediate region where the particle's thermal energy $(k_{B}T)$ and the rest-mass energy $(m{c}^2)$ do not differ significantly, i.e., $k_{B}T\sim m{c}^2$. However, the Fermi energy $(k_B{T}_F)$ is larger than the thermal energy and the normalized chemical energy ($\xi =\mu /k_{B}T$) is positive and finite. Two different parameter regimes with $\beta \equiv k_{B}T/m{c}^2<1$ and $\beta >1$, relevant for astrophysical plasmas, are defined, and the existence of small amplitude ion-acoustic solitons in these regimes are studied, including the critical cases where the known KdV (Korteweg-de Vries) theory fails. We show that while the solitons with both the positive (compressive) and negative (rarefactive) potentials coexist in the case of $\beta <1$, only compressive solitons can exist in the other regime $(\beta >1)$. Furthermore, while the rarefactive solitons within the parameter domains of $\beta$ and $\xi$ can evolve with increasing amplitude and hence increasing energy, the energy of compressive solitons reaches a steady state.

23 pages, 8 figures; To appear in Scientific Reports (Nature)

References in corpus (3)

• Highly compact neutron stars and screening mechanisms. I. Equilibrium and stability
• Large amplitude electromagnetic solitons in a fully relativistic magnetized electron-positron-pair plasma
• Ion-acoustic solitary waves in a partially degenerate plasma

Cited by in corpus (2)

• Rayleigh-Taylor instability in inhomogeneous relativistic classical and degenerate electron-ion magnetoplasmas
• Chaos in the dynamics of electromagnetic solitons in relativistic degenerate plasmas