larger than the observed dark energy density, V ρ0,crit 10−29
g/cm3
, by
a factor of order 10
56
. There are other unknown contributions to the vacuum energy that might cancel this contribution, coming from fluctuations
in fields at higher energies or from the field equations themselves, but this
cancelation would have to be precise to about 56 decimal places. There is
no known reason for this remarkable cancelation.
37
The discovery of dark
energy now adds a second problem: why
