发表机构
State University of Tetovo; Faculdade de Ciências da Universidade de Lisboa; Instituto de Astrofísica e Ciências do Espaço, Faculdade de Ciências da Universidade de Lisboa（泰托沃国立大学; 里斯本大学理学院; 里斯本大学理学院空间天体物理与科学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文利用弦论T-对偶性引入零点长度，构建单尺度Alcubierre曲速几何，消除轮廓收缩发散，但仍是有效假设且需奇异物质。
AI 中文摘要
弦论T-对偶性，通过其与路径积分对偶性的对应关系，赋予低能传播子一个零点长度$l_0=2\pi\sqrt{\alpha'}$，该长度软化了引力场的短距离行为。受由相应涂抹源得到的规则黑洞构造的启发，我们通过将曲速轮廓与该源的互补累积质量分数相关联，构建了一个T-对偶启发的Alcubierre几何。对于有效单尺度选择$f(r_s)=1-r_s^3/(r_s^2+l^2)^{3/2}$，其中$l^2=R^2+l_0^2$，该度规在气泡中心是$C^2$光滑的，在其他地方光滑，而能量密度、其体积积分和York展开式均以闭合形式给出。特别地，在几何单位制下$E=-(15\pi/1024)v_s^2 l$，且$|\rho_E|$受常数乘以$v_s^2/l^2$的界限约束。因此，在该单尺度族内，该模型消除了与固定速度下轮廓收缩极限$R\to 0$相关的发散，因为$l$不能低于$l_0$。这不应与常规Alcubierre薄壁极限（在固定宏观气泡半径下，独立壁厚趋于零）的正则化混淆。然而，我们强调，该构造是一种有效假设，而非从弦修正场方程推导而来：$R$是宏观轮廓尺度，选择$l^2=R^2+l_0^2$是一种插值，经典$l_0\to 0$极限仍是光滑厚壁轮廓，而非分布式的Alcubierre顶帽。奇异物质仍然是必需的，并且在没有显式重整化应力张量计算的情况下，不声称半经典稳定性或修正的量子能量不等式。
英文摘要
String T-duality, through its correspondence with path-integral duality, endows the low-energy propagator with a zero-point length $l_0=2π\sqrt{α'}$ that softens the short-distance behavior of gravitational fields. Motivated by the regular black-hole construction obtained from the corresponding smeared source, we formulate a T-duality-inspired Alcubierre geometry by identifying the warp profile with the complementary cumulative mass fraction of that source. For the effective one-scale choice $f(r_s)=1-r_s^3/(r_s^2+l^2)^{3/2}$, with $l^2=R^2+l_0^2$, the metric is $C^2$ at the bubble center and smooth elsewhere, while the energy density, its volume integral, and the York expansion are available in closed form. In particular, $E=-(15π/1024)v_s^2 l$ in geometric units and $|ρ_E|$ is bounded by a constant times $v_s^2/l^2$. Within this one-scale family, the model therefore removes the divergence associated with the profile-contraction limit $R\to 0$ at fixed velocity, because $l$ cannot fall below $l_0$. This should not be confused with a regularization of the conventional Alcubierre thin-wall limit at fixed macroscopic bubble radius, in which an independent wall thickness is taken to zero. We emphasize, however, that the construction is an effective ansatz rather than a derivation from string-corrected field equations: $R$ is a macroscopic profile scale, the choice $l^2=R^2+l_0^2$ is an interpolation, and the classical $l_0\to 0$ limit remains a smooth thick-walled profile rather than the distributional Alcubierre top hat. Exotic matter remains necessary, and neither semiclassical stability nor a modified quantum energy inequality is claimed without an explicit renormalized stress-tensor calculation.
Comments11 pages
