The solid lower limit on deuterium production makes a solid upper limit for the baryon to photon ratio. There is more of a problem at the upper limit for deuterium. I will give each of the different upper limits and the implied lower limit for the baryon to photon ratio.

First, the lower limit for deuterium;

The evolution model of Hata et al. 95 gives as an upper limit

The model of CST95b gives

Comparing this to the production of deuterium as a function of the baryon to photon ratio from the graph:

We see that the upper limit to the baryon to photon ratio is

while the lower limit is model dependant. From Hata et al. 95 we get

and from CST95b we have

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