标题： 投影霍拉瓦引力高能极限下的散射振幅 显示英文标题

标题： Scattering amplitudes in high-energy limit of projectable Horava gravity

摘要： 我们研究了可投影Hořava引力在高能极限下的情况，并使用规范计算机代数系统计算了规范化的引力子散射振幅。我们在总动量为零的碰撞情形下分析了这些振幅的性质。振幅随碰撞能量的增长方式与树级幺正性一致。我们讨论了它们的角度依赖性，并得出了微分截面的表达式，该表达式恰好只取决于耦合常数的基本组合。我们的一个关键结果是，当动能Lagrangian中的耦合常数 $\lambda$ 被取到无穷大时——这对应于理论候选的渐近自由紫外不动点值——任意动力学情况下的振幅都是有限的。我们提出了一个修正后的行动，它在 $\lambda=\infty$ 处产生了相同的振幅，从而确立了可投影Hořava引力在 $\lambda\to\infty$ 极限下是规则的。作为辅助结果，我们推导了非相对论规范理论中振幅的广义Ward恒等式。 显示英文摘要

摘要： We study the high-energy limit of projectable Ho\v rava gravity using on-shell graviton scattering amplitudes. We compute the tree-level amplitudes using symbolic computer algebra and analyze their properties in the case of collisions with zero total momentum. The amplitudes grow with collision energy in the way consistent with tree-level unitarity. We discuss their angular dependence and derive the expression for the differential cross section that happens to depend only on the essential combinations of the couplings. One of our key results is that the amplitudes for arbitrary kinematics are finite when the coupling $\lambda$ in the kinetic Lagrangian is taken to infinity -- the value corresponding to candidate asymptotically free ultraviolet fixed points of the theory. We formulate a modified action which reproduces the same amplitudes and is directly applicable at $\lambda=\infty$, thereby establishing that the limit $\lambda\to\infty$ of projectable Ho\v rava gravity is regular. As an auxiliary result, we derive the generalized Ward identities for the amplitudes in non-relativistic gauge theories.