标题： BPS杂质模型中的kink-kink解 显示英文标题

标题： Kink-kink solutions in BPS impurity models

摘要： 我们证明了BPS杂质理论可能支持BPS孤子-孤子解，即描述两个相隔任意距离的孤子的能量退化的解族。 这需要一个奇异杂质。 作为一个例子，我们考虑与这种BPS杂质耦合的sine-Gordon模型和$\phi^6$模型。 有趣的是，得到的解分别与双sine-Gordon孤子和Christ-Lee孤子相同。 我们还研究了模空间上的谱流。 所有模式都有奇数个节点，以抵消杂质的奇异性。 显示英文摘要

摘要： We show that BPS-impurity theories may support BPS kink-kink solutions i.e., an energetically degenerated family of solutions describing two kinks at any mutual distance. This requires a singular impurity. As an example we consider the sine-Gordon and $\phi^6$ models coupled with such a BPS impurity. Interestingly, obtained solutions are identical to double sine-Gordon kinks and Christ-Lee kinks respectively. We also study the spectral flow on the moduli space. All the modes have an odd number of nodes to cancel the singularity of the impurity.