Inter-universal Teichmuller Theory I: Construction of Hodge Theaters
Inter-universal Teichmuller Theory I: Construction of Hodge Theaters
Inter-universal Teichmuller Theory I: Construction of Hodge Theaters
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INTER-UNIVERSAL TEICHMÜLLER THEORY I 67<br />
for the resulting characteristic splitting <strong>of</strong> the Frobenioid Cv<br />
⊢ def<br />
= C v , i.e., so that we<br />
may think <strong>of</strong> the pair (O ⊲ (Cv ⊢ ),τv ⊢ ) as the object <strong>of</strong> TM ⊢ determined by K v ;<br />
D ⊢ v<br />
for the object <strong>of</strong> TM ⊢ determined by A Dv ;<br />
F ⊢ v<br />
def<br />
=(C ⊢ v , D ⊢ v ,τ ⊢ v )<br />
for the [ordered] triple consisting <strong>of</strong> Cv ⊢ , Dv ⊢ ,andτv ⊢ . Thus, the object (O ⊲ (Cv ⊢ ),τv ⊢ )<br />
<strong>of</strong> TM ⊢ is isomorphic to Dv ⊢ .Moreover,Cv ⊢ (respectively, Dv ⊢ ; Fv ⊢ )maybealgorithmically<br />
reconstructed from F v<br />
(respectively, D v ; F v<br />
).<br />
(iii) Next, let us observe that p v ∈ K v [cf. §0] may be thought <strong>of</strong> as a(n) [nonidentity]<br />
element <strong>of</strong> the noncompact factor Φ C ⊢<br />
v<br />
[i.e., the factor denoted by a “→” in<br />
the definition <strong>of</strong> TM ⊢ ] <strong>of</strong> the object (O ⊲ (Cv ⊢ ),τv ⊢ )<strong>of</strong>TM ⊢ . This noncompact factor<br />
Φ C ⊢ v<br />
is isomorphic, as a topological monoid, to R ≥0 ;letuswriteΦ C ⊢ v<br />
additively<br />
and denote by log(p v ) the element <strong>of</strong> Φ C ⊢ v<br />
determined by p v . Thus, relative to<br />
the natural action [by multiplication!] <strong>of</strong> R ≥0 on Φ C<br />
⊢<br />
v<br />
, it follows that log(p v )isa<br />
generator <strong>of</strong> Φ C<br />
⊢<br />
v<br />
. In particular, we may form a new topological monoid<br />
Φ C Θ<br />
v<br />
def<br />
= R ≥0 · log(p v ) · log(Θ)<br />
isomorphic to R ≥0 that is generated by a formal symbol “log(p v )·log(Θ) = log(p log(Θ)<br />
v )”.<br />
Moreover, if we denote by O × the compact factor <strong>of</strong> the object (O ⊲ (C ⊢ Cv<br />
⊢ v ),τv ⊢ )<strong>of</strong><br />
TM ⊢ , and set O × def<br />
= O × , then we obtain a new split Frobenioid (C Θ Cv<br />
Θ Cv<br />
⊢ v ,τv Θ ), isomorphic<br />
to (Cv ⊢ ,τv ⊢ ), such that<br />
O ⊲ (C Θ v )=O × C Θ v<br />
× Φ C Θ<br />
v<br />
— where we note that this equality gives rise to a natural isomorphism <strong>of</strong> split Frobenioids<br />
(C ⊢ v ,τ ⊢ v ) ∼ → (C Θ v ,τ Θ v ), obtained by “forgetting the formal symbol log(Θ)”. In<br />
particular, we thus obtain a natural isomorphism<br />
F ⊢ v<br />
∼<br />
→F Θ v<br />
—wherewewriteFv<br />
Θ def<br />
= (Cv Θ , Dv Θ ,τv Θ ) for the [ordered] triple consisting <strong>of</strong> Cv Θ ,<br />
Dv<br />
Θ def<br />
= Dv ⊢ , τv Θ . Finally, we observe that Fv Θ may be algorithmically reconstructed<br />
from F v<br />
.<br />
Remark 3.4.1. A similar remark to Remark 3.2.1 [i.e., concerning the phrase<br />
“reconstructed category-theoretically”] applies to the phrase “algorithmically reconstructed”<br />
that was applied in the discussion <strong>of</strong> Example 3.4.