113
Indeed:
From:
https://www.academia.edu/75787512/The_Theory_of_String_A_Candidate_for_a_G
eneralized_Unification_Model
The Einstein’s field equation and the String Theory.
The Einstein’s field equation which includes the cosmological constant is:
μν
μν
μν
GT
μν
(8)
where
μν
is the Ricci tensor, its trace, the cosmological constant,
μν
the metric
tensor of the space geometry, G the Newton’s gravitational constant and
μν
the tensor
representing the properties of energy, matter and momentum.
The left hand-side of (8) represents the gravitational field and, consequently, the
warped space-time, while the right hand-side represents the matter, i.e. the sources of
the gravitational field.
In string theory the gravity is related to the gravitons which are bosons, whereas the
matter is related to fermions. It follows that the left and right hand of (8) may be
respectively related to the action of bosonic and of superstrings.
The actions of bosonic string and superstring (also containing fermions) are
connected by the Palumbo-Nardelli relation (Palumbo et al. 2005):