Code package for calculating modified cosmic ionization and thermal histories with dark matter and other exotic energy injections

Journal Article · 30 January 2020 · Physical Review D

DOI: https://doi.org/10.1103/PhysRevD.101.023530 · OSTI ID:1596611

Liu, Hongwan ^[1]; Ridgway, Gregory W. ^[2]; Slatyer, Tracy R.  ^[3]

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1. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics; Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences; Massachusetts Institute of Technology
2. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics
3. Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States). Center for Theoretical Physics; Inst. for Advanced Study, Princeton, NJ (United States). School of Natural Sciences

Here we present a new public Python package, DarkHistory, for computing the effects of dark matter annihilation and decay on the temperature and ionization history of the early universe. DarkHistory simultaneously solves for the evolution of the free electron fraction and gas temperature, and for the cooling of annihilation/decay products and the secondary particles produced in the process. Consequently, we can self-consistently include the effects of both astrophysical and exotic sources of heating and ionization, and automatically take into account backreaction, where modifications to the ionization/temperature history in turn modify the energy-loss processes for injected particles. We introduce a number of worked examples, demonstrating how to use the code in a range of different configurations, in particular for arbitrary dark matter masses and annihilation/decay final states. Possible applications of DarkHistory include mapping out the effects of dark matter annihilation/decay on the global 21 cm signal and the epoch of reionization, as well as the effects of exotic energy injections other than dark matter annihilation/decay. The code is available at https://github.com/hongwanliu/DarkHistory with documentation at https://darkhistory.readthedocs.io. Data files required to run the code can be downloaded at https://doi.org/10.7910/DVN/DUOUWA.

• Research Organization: Massachusetts Inst. of Technology (MIT), Cambridge, MA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25); MIT Research Support Committee; National Science Foundation (NSF)
• Grant/Contract Number: SC0013999
• OSTI ID: 1596611
• Report Number(s): MIT-CTP--5113; arXiv:1904.09296
• Journal Information: Physical Review D, Journal Name: Physical Review D Journal Issue: 2 Vol. 101; ISSN PRVDAQ; ISSN 2470-0010
• Publisher: American Physical Society (APS)Copyright Statement
• Country of Publication: United States
• Language: English