Parabolic equations with delay has been widely used in scientific and engineering fields.In this paper,we consider the time approximation of parabolic equations with delay.Firstly,we prove the stability of variable step-size BDF2 method for parabolic equations with delay.Then,we derive a higher order numerical approximation by reconstruction.Finally,we obtain a posteriori estimates of variable step-size BDF2 method for the equations.The paper mainly deals with the following linear delay parabolic equation u'(t)+ Au(t)+ Bu(?(t))= f(t),t ?[0,T],u(t)=? t?[t-1,0].We study a posteriori error estimates of the variable step-size BDF2 method for it.The conclusions are as follows:1.The stability of variable step-size BDF2 method for linear delay parabolic equations is proved.2.A posteriori error estimates of variable step-size BDF2 method(including two reconstructions)for linear delay parabolic equations are given. |