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.

Background

The paper develops methods to capture p-adic Hodge parameters of a non-critical semistable (φ,Γ)-module D via explicit locally analytic representations and extension groups. A key construction is a conjectural representation π1+(\underline{φ},) together with a surjective map t_D+ from Ext1_G(π{\natural}{}(\underline{φ},), π_1+(\underline{φ},)) to a direct sum of de Rham deformation data, which is expected to control Hodge-theoretic information.

The maps γD+ and g_D+ relate parabolic deformation spaces of D to the global extension space Ext1_G(π{\natural}{}(\underline{φ},), π_1+(\underline{φ},)) and to \overline{Ext}1(D,D), respectively, while f_D is a splitting of the natural exact sequence identifying de Rham and monodromy contributions to \overline{Ext}1(D,D). The conjecture asks for precise compatibilities among these maps and for the reconstruction of the Hodge filtration from ker(t_D+), which would strengthen the connection between locally analytic representation theory and p-adic Hodge theory in the semistable setting.

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).

Towards the $p$-adic Hodge parameters in semistable representations of $\mathrm{GL}_n(\mathrm{Q}_p)$  (2604.01846 - He, 2 Apr 2026) in Conjecture (label: descibeimagetDGL2), Subsection 6: Further comments