A Hybrid Algorithm Based on Optimal Quadratic Spline Collocation and Parareal Deferred Correction for Parabolic PDEs

Figure 4

Stability region (doted area) using implicit Euler integrators for the coarse propagators and explicit Euler integrators for the fine propagators after 1 iteration (a), 3 iterations (b), 4 iterations (c), and 5 iterations (d). The -axis is and the -axis is , where , and .

(a)

(b)

(c)

(d)