Radiative QED corrections to one-photon transition rates in hydrogen atom at finite temperatures

Within the framework of QED theory at finite temperature the thermal radiative corrections to spontaneous one-photon transition rates in hydrogen atom are investigated. The radiative one-loop self-energy corrections are described in the thermal case. Closed analytical expressions are derived and their numerical calculations for the spontaneous decay rate of the $2p$ state are carried out. Dominance of thermal radiative corrections to spontaneous Ly${}_{\alpha }$ decay rate over ordinary induced transition rate up to temperatures $T<6000$ K is demonstrated.