2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/196141We have considered phi^4 theory in higher dimensions. Using functional diagrammatic approach, we computed the one-loop correction to effective potential of the scalar field in five dimensions. It is shown that phi^4 theory can be regularised in five dimensions. Temperature dependent one-loop correction and critical temperature T_c are computed and T_c depends on the fundamental scale M of the theory. A brief discussion of symmetry restoration is also presented. The nature of phase transitions is examined and is of second order8 pages, 5 figures. To appear in IJMPAHigh Energy Physics - TheoryGeneral Relativity and Quantum Cosmologytext