Is M_{Pl} the Planck mass or the reduced Planck mass?

In summary, the value of M_{Pl} used in the Planck (CMB) collaboration's observation papers, such as the one referenced in the link provided, can refer to either the Planck mass or the reduced Planck mass. The reduced Planck mass is defined as 2.176 434 x 10-8 kg according to the NIST webpage, and can be found in the literature with a diagonal line through the letters P or Pl in the subscript. It is recommended to check the specific source for clarification on which value is being used.
  • #1
Alpha2021
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What is the value of M_{Pl} used in the Planck (CMB) collaboration's observation papers, such as the one referenced in this link: https://arxiv.org/pdf/1807.06211.pdf. Specifically, I am wondering if it refers to the Planck mass or the reduced Planck mass?
 
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  • #3
Thanks for your kind reply.
Definition of reduced Planck mass can be found here.
The problem is that M_{Pl} is used in the literature interchangeably as Planck mass or reduced Planck mass. Did you see anywhere in Planck's papers where they define M_{Pl}?
 
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  • #4
I found in

https://www.cosmos.esa.int/web/planck
> https://www.aanda.org/articles/aa/full_html/2020/09/aa33910-18/aa33910-18.html#S1
1683151818052.png

You may get value of m_pl they use.
 
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  • #6
Alpha2021 said:
What is the value of M_{Pl} used in the Planck (CMB) collaboration's observation papers, such as the one referenced in this link: https://arxiv.org/pdf/1807.06211.pdf. Specifically, I am wondering if it refers to the Planck mass or the reduced Planck mass?
Better practice, although you are right in asking as some authors are sloppy in their typesetting, is to indicate the reduced Planck mass with diagonal line through the letters P or Pl in the subscript, just as one indicates the reduced Planck's constant with a diagonal link through the symbol "h" for Planck's constant.
 

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