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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146 SHINICHI MOCHIZUKI<br />
is unique. Then by applying Propositions 4.8, 6.6, and Corollaries 5.6, 6.12, one<br />
may verify analogues <strong>of</strong> these results for such Θ ±ell NF-<strong>Hodge</strong> theaters. In a similar<br />
vein, one may glue a D-Θ ±ell -<strong>Hodge</strong> theater to a D-ΘNF-<strong>Hodge</strong> theater to obtain a<br />
“D-Θ ±ell NF-<strong>Hodge</strong> theater” [cf. Definition 6.13, (ii), below]. We leave the routine<br />
details to the reader.<br />
Remark 6.12.3.<br />
(i) One way to think <strong>of</strong> the notion <strong>of</strong> a ΘNF-<strong>Hodge</strong> theater studied in §4 isas<br />
a sort <strong>of</strong><br />
total space <strong>of</strong> a local system <strong>of</strong> F l -torsors<br />
over a “base space” that represents a sort <strong>of</strong> “homotopy” between a number field<br />
and a Tate curve [i.e., the elliptic curve under consideration at the v ∈ V bad ]. From<br />
this point <strong>of</strong> view, the notion <strong>of</strong> a Θ ±ell -<strong>Hodge</strong> theater studied in the present §6<br />
may be thought <strong>of</strong> as a sort <strong>of</strong><br />
total space <strong>of</strong> a local system <strong>of</strong> F ⋊±<br />
l<br />
-torsors<br />
over a similar “base space”. Here, it is interesting to note that these F l -andF⋊± l<br />
-<br />
torsors arise, on the one hand, from the l-torsion points <strong>of</strong> the elliptic curve under<br />
consideration, hence may be thought <strong>of</strong> as<br />
discrete approximations <strong>of</strong><br />
[the geometric portion <strong>of</strong>] this elliptic curve over a number field<br />
[cf. the point <strong>of</strong> view <strong>of</strong> scheme-theoretic <strong>Hodge</strong>-Arakelov theory discussed in [HA-<br />
SurI], §1.3.4]. On the other hand, if one thinks in terms <strong>of</strong> the tempered fundamental<br />
groups <strong>of</strong> the Tate curves that occur at v ∈ V bad , then these F l -andF⋊± l<br />
-torsors<br />
may be thought <strong>of</strong> as<br />
finite approximations <strong>of</strong> the copy <strong>of</strong> “Z”<br />
that occurs as the Galois group <strong>of</strong> a well-known tempered covering <strong>of</strong> the Tate<br />
curve [cf. the discussion <strong>of</strong> [EtTh], Remark 2.16.2]. Note, moreover, that if one<br />
works with Θ ±ell NF-<strong>Hodge</strong> theaters [cf. Remark 6.12.2, (ii)], then one is, in effect,<br />
working with both the additive and the multiplicative structures <strong>of</strong> this copy<br />
<strong>of</strong> Z — although, unlike the situation that occurs when one works with rings,<br />
i.e., in which the additive and multiplicative structures are “entangled” with<br />
one another in some sort <strong>of</strong> complicated fashion [cf. the discussion <strong>of</strong> [AbsTopIII],<br />
Remark 5.6.1], if one works with Θ ±ell NF-<strong>Hodge</strong> theaters, then each <strong>of</strong> the additive<br />
and multiplicative structures occurs in an independent fashion [i.e., in the form <strong>of</strong><br />
Θ ±ell - and ΘNF-<strong>Hodge</strong> theaters], i.e., “extracted” from this entanglement.<br />
(ii) At this point, it is useful to recall that the idea <strong>of</strong> a distinct [i.e., from the<br />
copy <strong>of</strong> Z implicit in the “base space”] “local system-theoretic” copy <strong>of</strong> Z occurring<br />
over a “base space” that represents a number field is reminiscent not only <strong>of</strong> the<br />
discussion <strong>of</strong> [EtTh], Remark 2.16.2, but also <strong>of</strong> the Teichmüller-theoretic point <strong>of</strong><br />
view discussed in [AbsTopIII], §I5. That is to say, relative to the analogy with p-adic<br />
Teichmüller theory, the “base space” that represents a number field corresponds to