SimpleBounce: A simple package for the false vacuum decay

We present SimpleBounce, a C++ package for finding the bounce solution for the false vacuum decay. This package is based on a flow equation which is proposed by the author R. Sato (2020) and solves Coleman–Glaser–Martin’s reduced problem (S. R. Coleman et al. 1978): the minimization problem of the kinetic energy while fixing the potential energy. The bounce configuration is obtained by a scale transformation of the solution of this problem. For models with 1–8 scalar field(s), the bounce action can be calculated with O(0.1) % accuracy in O(0.1) s. This package is available at http://github.com/rsato64/SimpleBounce. Program title: SimpleBounce. CPC Library link to program files: http://dx.doi.org/10.17632/g74z22ryht.1 Developer’s repository link: http://github.com/rsato64/SimpleBounce Licensing provisions: GPLv3. Programming language: C++ Nature of problem: The decay rate of the false vacuum can be evaluated by using Euclidean path integral formalism, and the bounce solution is a saddle point of this path integral. The bounce solution and its Euclidean action are numerically evaluated. Solution method: The bounce solution is obtained as a fixed point of gradient flow equation. Additional comments including restrictions and unusual features: The computation is fast and stable against a choice of initial configuration. References: [1] R. Sato, Simple Gradient Flow Equation for the Bounce Solution, 10.1103/PhysRevD.101.016012Phys. Rev. D 101 no. 1, (2020) 016012, arXiv:1907.02417[hep-ph]