arXivDaily arXiv每日学术速递 周一至周五更新
arXiv周末暂无论文更新,休息一下吧,周末愉快~~
arXiv 2603.03548math.AP
收藏

非径向液体兰姆-埃门德星的线性稳定性

Nonradial linear stability of liquid Lane-Emden stars

Delft Institute of Applied Mathematics, Delft University of Technology(代尔夫特应用数学研究所,代尔夫特理工大学)

King Ming Lam

AI总结:

研究证明液态兰姆-埃门德星在非径向无旋扰动下稳定,但其稳定性受纯径向模式稳定性的限制,且无法完全控制梯度项。

摘要:

经典恒星模型是兰姆-埃门德星,其动力学由欧拉-泊松方程支配。我们考虑一种具有

英文摘要:

The classical model of a star is the Lane-Emden star with dynamics governed by the Euler-Poisson equations. We consider the case of a liquid star with a "stiffened gas" equation of state $p=ρ^γ-1$. We derive the full 3D linearised Euler-Poisson system around liquid Lane-Emden stars with no symmetry assumptions on the perturbations and show that the associated linear operator $\mathbf L$ is non-negative whenever the radial mode is non-negative. We show that $\mathbf L$ has an infinite-dimensional kernel each element of which corresponds to a linearly growing solution to the linearised system. When restricted to irrotational perturbations and modding out the three kernel elements corresponding to momentum conservation, however, we prove that $\mathbf L$ is strictly positive with coercivity bound $\langle\mathbf L\boldsymbolθ,\boldsymbolθ\rangle_{\barρ}\gtrsim\|\boldsymbolθ\|_{L^2(B_R)}^2$. Hence we demonstrate that the liquid Lane-Emden stars are stable against non-radial irrotational perturbations whenever the purely radial mode is stable, improving upon previous results that dealt only with purely radial perturbations. However, the stability might not be as strong as one might hope, as we prove that $\|\nabla\boldsymbolθ\|_{L^2(B_R)}^2$ cannot be controlled even in this case.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑