96 Chapter 4: Fluctuations in Jet Tomography from [381, 388]; for gluons and light quarks, the initial distributions are com- puted at leading order as in [277]. P ( E$_{i}$ → E$_{f}$ ) is the energy loss probability, D ( Q → H$_{Q}$ ) is the fragmentation function of quark Q to hadron H$_{Q}$ , and f ( H$_{Q}$ → e ) is the decay function of hadron H$_{Q}$ into the observed single elec- tron. We use the same mass and factorization scales as in [389] and employ the CTEQ5M parton densities [161, 390] with no intrinsic k$_{T}$ . As in [389] we neglect shadowing of the nuclear parton distribution in this application. We assume that the final quenched energy, E$_{f}$ , is large enough that the Eikonal approximation can be employed. We also assume that in Au+Au collisions, the jet fragmentation function into hadrons is the same as in e $^{+}$e − collisions. This is expected to be valid in the deconfined pQCD medium case, where hadronization of Q → H$_{Q}$ cannot occur until the quark emerges from the deconfined sQGP medium. The main difference between our previous calculation [374] and the present one is the inclusion of two new physics components in the energy loss proba- bility P ( E$_{i}$ → E$_{f}$ ). First, P ( E$_{i}$ → E$_{f}$ ) is generalized to include for the first time both elastic and inelastic energy loss and their fluctuations. We note that Vitev [391–393] was the first to generalize GLV to include initial state elastic energy loss effects in D+Au. In this work, Eq. (4.2) extends the formalism to include final state elastic loss effects in A + A . The second major change relative to our previous applications is that we