Holographic spectral function of fermion in instantonic plasma

Using the gauge-gravity duality, we investigate the fermionic correlation function in the D(-1)-D3 brane system which describes the instantonic plasma in holography. In this system, the charge of the D(-1) brane as the D-instanton gives the gluon condensate. To simplify the holographic setup, we first reduce briefly the ten-dimensional supergravity background produced by D(-1)-D3-branes to an equivalently five-dimensional background. Then using the standard method for computing the Green function in the AdS/CFT dictionary, we derive the equations for the fermionic correlation functions and solve them numerically with the infalling boundary condition. Our numerical results illustrate that the fermionic correlation function as spectral function includes two branches of the dispersion curves whose behavior is very close to the results obtained from the method of hard thermal loop. And the effective mass generated by the medium effect of fermion splits into two values due to the spin-dependent interactions induced by instantons. Therefore, this work in holography demonstrates the instantonic configuration is very influential to the fermionic plasmino in plasma.
Comment: 19 pages, 5 figures