New iterations with errors for approximating common fixed points for two generalized asymptotically quasi-nonexpansive nonself-mappings
Sornsak Thianwan · Mathematical Notes · 2011
Let X be a real uniformly convex Banach space and C a nonempty closed convex nonexpansive retract of X with P as a nonexpansive retraction. Let T 1, T 2: C → X be two uniformly L-Lipschitzian, generalized asymptotically quasi-nonexpansive non-self-mappings of C satisfying condition A′ with sequences {k } and {δ } ⊂ [1, ∞),, i = 1, 2, respectively such that Σ =1 ∞ (k () − 1) < ∞, Σ =1 () δ () < ∞, and F = F(T 1) ∩ F(T 2) ≠ ∅. For an arbitrary x 1 ∈ C, let {x n } be the sequence in C defined by $$ \begin{gathered} y_n = P\left( {\left( {1 - \beta _n - \gamma _n } \right)x_n + \beta _n T_2 \left( {PT_2 } \right)^{n - 1} x_n + \gamma _n v_n } \right), \hfill \\ x_{n + 1} = P\left( {\left( {1 - \alpha _n - \lambda _n } \right)y_n + \alpha _n T_1 \left( {PT_1 } \right)^{n - 1} x_n + \lambda _n u_n } \right), n \geqslant 1, \hfill \\ \end{gathered} $$ where {α n }, {β n }, {γ n } and {λ n } are appropriate real sequences in [0, 1) such that Σ =1 ∞ ] γ n < ∞, Σ =1 ∞ λ n < ∞, and {u n }, }v n } are bounded sequences in C. Then {x n } and {y n } converge strongly to a common fixed point of T 1 and T 2 under suitable conditions.