Document Type : Research Paper
Department of Mathematics, College of Education for Pure Sciences, Tikrit University, Tikrit, Iraq
Department of Mathematics, College of Basic Education, Mustansiriyah University, Baghdad, Iraq
Department of Mathematics, College of Education, Al- Hamdaniya University, Mosul, Iraq
Department of Mathematics, College of Sciences, Kirkuk University, Kirkuk, Iraq
Throughout this manuscript, we show time periodic solutions to a linear diffusion parabolic equation with Diriclet condition. Based on the topological degree theorem, we prove a time periodic solutions of the system such that we found the fixed point when the domain of the solution is sufficiently small.