Compatibility of t_D^+ and γ_D^+ and determination of the Hodge filtration
Establish that, for every u in the set of minimal length representatives _n^{S_0}, the identity t_D^+ ∘ γ_D^+|_{\overline{Ext}^1_{S_0(u)}(D,D)} = f_D ∘ ι_{S_0(u)} holds under the splitting f_D of Proposition 4.?. Here t_D^+ is the surjection t_D^+: Ext^1_G(π_{\natural}^{}(\underline{φ},), π_1^+(\underline{φ},)) → Ext^{1,∘}_{\varphi^f}(D[1/t], D[1/t]) ⊕ End_{Hodge-filtration}(D) defined in the Further comments subsection, γ_D^+ is the map from the direct sum of parabolic deformation spaces \bigoplus_{u∈_n^{S_0}} \overline{Ext}^1_{S_0(u)}(D,D) to Ext^1_G(π_{\natural}^{}(\underline{φ},), π_1^+(\underline{φ},)), ι_{S_0(u)} is the natural inclusion \overline{Ext}^1_{S_0(u)}(D,D) ↪ \overline{Ext}^1(D,D), and g_D^+ is the natural surjection \bigoplus_{u∈_n^{S_0}} \overline{Ext}^1_{S_0(u)}(D,D) → \overline{Ext}^1(D,D). In particular, show that g_D^+ factors through γ_D^+ with g_D^+ = t_D^+ ∘ γ_D^+. Furthermore, ascertain that the kernel of t_D^+ determines the Hodge filtration ^H_\bullet(D) of the semistable (φ,Γ)-module D.
References
Conjecture Let u\in_n{S_0}. Let \iota_{S_0(u)}:\overline{}{1}_{S_0(u)}(D,D)\hookrightarrow \overline{}{1}(D,D) be the natural inclusion. Recall the surjection g+{D}:\bigoplus{u\in_n{S_0}\overline{}{1}_{S_0(u)}(D,D)\rightarrow \overline{}{1}(D,D). (1) Under the splitting in Proposition \ref{splitingforext1gps}, t+{D}\circ\gamma+{D}|{\overline{}{1}{S_0(u)}(D,D)} is equal to f_{D}\circ\iota_{S_0(u)}. Moreover, g+_{D} factors through \gamma_{D}, and g{+}{D}=t+{D}\circ\gamma+_{D}. (2) \ker(t+_{D}) determines _{H}{\bullet}(D).