Let' s calculate one-loop counterterms of minimal fourth order operator using methods described in Calculating one-loop counterterms. The operator is: Dij=δij◻2+Wμνij∇μ∇ν+Mij
The input quantities needed for the algorithm described in Calculating one-loop counterterms are: Kλμγδαβ=δβα13(gλμgγδ+gλγgμδ+gλδgμγ),Sμνγαβ=0,Wμναβ=Wμναβ,Nμαβ=0,Mαβ=Mαβ,(Kn)−1αβ=δβα,Fμναβ=Fμναβ.
The following code produces the result:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 | //setup symmetries of Riemann tensor addSymmetries 'R_abcd' , - [[ 0 , 1 ]] .p , [[ 0 , 2 ], [ 1 , 3 ]] .p setSymmetric 'R_ab' addSymmetry 'W_lmab' , [[ 0 , 1 ]] .p def iK = 'iK_a^b = d_a^b' .t def K = ( 'K^lmcd_a^b = d_a^b*1/3*(g^lm*g^cd + g^lc*g^md + g^ld*g^mc)' ) .t def S = 'S^lmpab = 0' .t def W = 'W^lm_a^b = W^lm_a^b' .t def N = 'N^pab=0' .t def M = 'M_a^b = M_a^b' .t def F = 'F_lmab = F_lmab' .t def div = oneloopdiv4(iK, K, S, W, N, M, F) def counterterms = EliminateDueSymmetries > > div .counterterms counterterms = 'M^l_l = M' .t > > counterterms counterterms = 'W_lm^a_a = W_lm' .t > > counterterms counterterms = 'W^a_a = W' .t > > counterterms println counterterms |
> counterterms = (2/3)*F_{mb}^{e}_{a_{5}}*F^{mba_{5}}_{e}-(1/9)*W^{lm}*R_{lm} +(1/9)*R*W-M+(1/24)*W^{bda}_{a_{5}}*W_{bd}^{a_{5}}_{a} +(1/48)*W_{d}^{da}_{a_{5}}*W_{b}^{ba_{5}}_{a} -(32/135)*R^{al}*R_{al}+(44/135)*R**2 |
Multiplying the produced result by 1/16π(d−4) and integrating over the space-time volume gives:
Γ(1)∞=116π(d−4)∫d4x√−g(−M+23FνβϵρFνβρϵ−32135RμνRμν+44135R2+19RW−19RμνWμν+124WϵδαρWϵδρα+148WδδαρWββρα),
where Fμναβ is a curvature tensor with respect to the principal bundle, Rμν is a Ricci tensor, R is a Riemann scalar curvature, Mμμ=M, Wμναα=Wμν and Wαα=W.