标题： 温暖波暗物质中的自由流 显示英文标题

标题： Free Streaming in Warm Wave Dark Matter

摘要： 我们提供了一个数值计算暴胀后产生的标量场中自由流效应的框架。 首先，我们提供了设置场初始条件的详细方法。 该方法允许我们指定场的功率谱（在亚视界长度尺度上具有峰值且没有均匀场模式），并且重要的是，还能正确再现大长度尺度上的密度扰动行为，这与超视界绝热扰动一致。 然后，我们使用空间非均匀的克莱因-戈登方程演化场，包括膨胀和辐射源度规扰动的影响。 我们展示了重力如何增强，以及自由流如何消除场的初始绝热密度扰动，从而揭示了更底层的、不随时间变化的白噪声等曲率密度对比。 此外，我们探讨了场的非引力自相互作用（包括振荡子形成）对抑制动力学的影响。 作为本文的一部分，我们将我们的代码${\sf{Cosmic-Fields-Lite}}$（${\sf{CFL}}$）公开可用。 对于可观察的特征，我们的工作特别适用于轻/超轻暗物质场中的结构形成。 显示英文摘要

摘要： We provide a framework for numerically computing the effects of free-streaming in scalar fields produced after inflation. First, we provide a detailed prescription for setting up initial conditions in the field. This prescription allows us to specify the power spectra of the fields (peaked on subhorizon length scales and without a homogeneous field mode), and importantly, also correctly reproduces the behaviour of density perturbations on large length scales consistent with superhorizon adiabatic perturbations. We then evolve the fields using a spatially inhomogeneous Klein-Gordon equation, including the effects of expansion and radiation-sourced metric perturbations. We show how gravity enhances, and how free streaming erases the initially adiabatic density perturbations of the field, revealing more of the underlying, non-evolving, white-noise isocurvature density contrast. Furthermore, we explore the effect of non-gravitational self-interactions of the field, including oscillon formation, on the suppression dynamics. As part of this paper, we make our code, ${\sf{Cosmic-Fields-Lite}}$ (${\sf{CFL}}$), publicly available. For observationally accessible signatures, our work is particularly relevant for structure formation in light/ultralight dark matter fields.