Units of dtauda in CAMB

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Aviv Padawer-Blatt
Posts: 9
Joined: October 28 2021
Affiliation: University of Waterloo

Units of dtauda in CAMB

Post by Aviv Padawer-Blatt » July 09 2022

Hi!

In CAMB, the module equations.f90 has the dtauda function. I have found in the CAMB Notes that "everything is in conformal time and units of megaparsecs", but cannot find further information, and I do not know exactly how to take this. Does this imply that everything is in natural units, with the chosen reference unit being megaparsecs? Or are just distances measured in megaparsecs, and times (eg. tau in dtauda) measured in units of conformal time, rather than for example seconds or years? I really just want to know the units of tau.

Thank you!

Antony Lewis
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Re: Units of dtauda in CAMB

Post by Antony Lewis » July 11 2022

tau has units of megaparsec

Aviv Padawer-Blatt
Posts: 9
Joined: October 28 2021
Affiliation: University of Waterloo

Re: Units of dtauda in CAMB

Post by Aviv Padawer-Blatt » July 11 2022

Okay, thank you! And I'm sorry, I know this is simple, but that means the speed of light c has no units and its value is 1 then, correct?

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