c.l.

• CL

c.l.

1. Initialism of confidence level.

   Due to its effect on the expansion rate of the Universe during Big Bang nucleosynthesis (BBN), the theoretical expectations for the primordial abundances of light elements depend on N_ν. Astrophysical measurements of the primordial ⁴He and ²D abundances lead to a value of N_ν = ${\displaystyle 3.14_{-0.65}^{+0.70}}$  at 68% c.l., in very good agreement with the Standard Model expectation.^[1]

• L/C, LC, l.c., l/c, lc