ULYSSES, universal LeptogeneSiS equation solver: Version 2

ULYSSES is a Python package that calculates the baryon asymmetry produced from leptogenesis in the context of a type-I seesaw mechanism. In this release, the new features include code which solves the Boltzmann equations for low-scale leptogenesis; the complete Boltzmann equations for thermal leptogenesis applying proper quantum statistics without assuming kinetic equilibrium of the right-handed neutrinos; and, primordial black hole-induced leptogenesis. ULYSSES version 2 has the added functionality of a pre-provided script for a two-dimensional grid scan of the parameter space. As before, the emphasis of the code is on user flexibility, rapid evaluation and is publicly available at https://github.com/earlyuniverse/ulysses.

ULYSSES是一款用于计算I型跷跷板机制（type-I seesaw mechanism）框架下轻子生成过程所产生的重子不对称性的Python软件包。本次发布版本新增功能包括：面向低能标轻子生成的玻尔兹曼方程（Boltzmann equations）求解代码；无需假设右手中微子处于动力学平衡状态、采用严格量子统计的热轻子生成完整玻尔兹曼方程；以及原初黑洞（primordial black hole）诱导的轻子生成过程。ULYSSES 2版本新增了参数空间二维网格扫描的预置脚本功能。与过往版本一致，该代码的核心设计目标为保障用户灵活性与快速评估能力，其开源地址为https://github.com/earlyuniverse/ulysses。