PART I: Introduction and motivation The term “anabelian” was invented by Grothendieck, and a possible translation of it might be “beyond Abelian”. The corresponding mathematical notion of “anabelian Geometry” is vague as well, and roughly means that under certain “anabelian hypotheses” one has: ∗ ∗ ∗Arithmetic and Geometry are encoded in Galois Theory ∗ ∗ ∗ It is our aim to try to explain the above assertion by presenting/explaining some results in this direction. For Grothendieck’s writings concerning this the reader should have a look at [G1], [G2].
PART II: Grothendieck’s Anabelian Geometry The natural context in which the above result appears as a first prominent example is Grothendieck’s anabelian geometry, see [G1], [G2]. We will formulate Grothendieck’s anabelian conjectures in a more general context later, after having presented the basic facts about ´etale fundamental groups. But it is easy and appropriate to formulate here the so called birational anabelian Conjectures, which involve only the usual absolute Galois group.
P22 The result above by Mochizuki is the precursor of his much stronger result concerning hyperbolic curves over sub-p-adic fields as explained below.
PART III: Beyond Grothendieck’s anabelian Geometry
References Ihara, Y., On beta and gamma functions associated with the Grothendieck-Teichmller group II, J. reine angew. Math. 527 (2000), 1–11. Mochizuki, Sh., The profinite Grothendieck Conjecture for closed hyperbolic curves over number fields, J. Math. Sci. Univ Tokyo 3 (1966), 571–627. Mochizuki, The absolute anabelian geometry of hyperbolic curves, Galois theory and modular forms, 77–122, Dev. Math., 11, Kluwer Acad. Publ., Boston, MA, 2004. Nagata, M., A theorem on valuation rings and its applications, Nagoya Math. J. 29 (1967), 85–91. Nakamura, H., Galois rigidity of the ´ etale fundamental groups of punctured projective lines, J. reine angew. Math. 411 (1990) 205–216.
P10 The conclusion of this discussion is that with consistent identifications of copies of real numbers, one must in (1.5) omit the scalars j^2 that appear, which leads to an empty inequality. We voiced these concerns in this form at the end of the fourth day of discussions. On the fifth and final day,
Mochizuki tried to explain to us why this is not a problem after all. In particular, he claimed that up to the “blurring” given by certain indeterminacies the diagram does commute; it seems to us that this statement means that the blurring must be by a factor of at least O(l^2) rendering the inequality thus obtained useless. (google訳) 望月氏は、結局のところ、なぜこれが問題にならないのかを説明しようとしました。 特に、特定の不確定性によって与えられる「ぼやけ」までは、図は可換であると彼は主張した。 このステートメントは、ぼかしは少なくとも O(l^2) 倍でなければならず、こうして得られた不等式を役に立たなくすることを意味しているように私たちには思えます。
P9 2.2. Proof of [IUTT-3, Corollary 3.12]. As we indicated earlier, there is no clear distinction between abstract and concrete pilot objects in Mochizuki’s work, so it is argued in [IUTT-3, Corollary 3.12] that the multiradial algorithm [IUTT-3, Theorem 3.11]*12 implies that up to certain indeterminacies, e.g. (Ind 1,2,3) (without which the conclusion would be obviously false), this becomes an identification of concrete Θ-pilot objects and concrete q-pilot objects (encoded via their action on processions of tensor packets of log-shells), and then the inequality follows directly. 注) *12 We pause to observe that with the simplifications outlined above, such as identifying identical copies of objects along the identity, the critical [IUTT-3, Theorem 3.11] does not become false, but trivial.
P154 for the collection of data (a), (b), (c) regarded up to indeterminacies of the following two types:
(Ind1) the indeterminacies induced by the automorphisms of the procession of D-prime-strips Prc(n,◦DT);
(Ind2) for each vQ ∈ Vnon Q (respectively, vQ ∈ Varc Q ), the indeterminacies induced by the action of independent copies of Ism [cf. Proposition 1.2, (vi)] (respectively, copies of each of the automorphisms of order 2 whose orbit constitutes the poly-automorphism discussed in Proposition 1.2, (vii)) on each of the direct summands of the j+1 factors appearing in the tensor product used to define IQ(S± j+1;n,◦DvQ ) [cf. (a) above; Proposition 3.2, (ii)] —where we recall that the cardinality of the collection of direct summands is equal to the cardinality of the set of v ∈ V that lie over vQ.
(Ind3) as one varies m ∈ Z, the isomorphisms of (a) are “upper semicompatible”, relative to the log-links of the n-th column of the LGPGaussian log-theta-lattice under consideration, in a sense that involves certain natural inclusions “⊆” at vQ ∈ Vnon Q and certain natural surjections “↠” at vQ ∈ Varc Q —cf. Proposition 3.5, (ii), (a), (b), for more details.
(参考) http://ahgt.math.cnrs.fr/activities/workshops/MFO-RIMS23/ MFO-RIMS Tandem workshop 2023 - Arithmetic Homotopy and Galois Theory Sep. 24 to 29 (GE)/ Sep. 25 to 29 (JP), 2023 · Oberwolfach & RIMS Kyoto · Org.: B. Collas (RIMS), P. Dèbes (Lille), Y. Hoshi (RIMS), A. Mézard (ENS)
List of invited participants Antonin Assoun Université de Lille Pierre Dèbes Lille University Béranger Seguin Université de Lille
P10 The conclusion of this discussion is that with consistent identifications of copies of real numbers, one must in (1.5) omit the scalars j^2 that appear, which leads to an empty inequality. We voiced these concerns in this form at the end of the fourth day of discussions. On the fifth and final day,
Mochizuki tried to explain to us why this is not a problem after all. In particular, he claimed that up to the “blurring” given by certain indeterminacies the diagram does commute; it seems to us that this statement means that the blurring must be by a factor of at least O(l^2) rendering the inequality thus obtained useless. (google訳) 望月氏は、結局のところ、なぜこれが問題にならないのかを説明しようとしました。 特に、特定の不確定性によって与えられる「ぼやけ」までは、図は可換であると彼は主張した。 このステートメントは、ぼかしは少なくとも O(l^2) 倍でなければならず、こうして得られた不等式を役に立たなくすることを意味しているように私たちには思えます。
http://www3.nhk.or.jp/news/html/20230707/k10014121791000.html NHK 数学「ABC予想」新たな証明理論の研究発展させる論文に賞創設 20230707 数学の難問「ABC予想」を証明したとする日本の数学者の新たな理論をめぐって、研究を発展させる論文を対象に、100万ドルの賞金を贈呈する賞が国内のIT企業の創業者によって創設されることになりました。 ▽新たな発展を含む論文を毎年選び、最大で賞金10万ドル ▽理論の本質的な欠陥を示す論文を発表した最初の執筆者に対しては100万ドルを、 それぞれ贈呈するとしています。
http://ahgt.math.cnrs.fr/activities/ Anabelian Geometry and Representations of Fundamental Groups. Oberwolfach workshop MFO-RIMS Sep. 29-Oct. 4, 2024 Org.: A. Cadoret, F. Pop, J. Stix, A.. Topaz (J. Stixさん、IUT支持側へ)
Eine (n×n)-Matrix A mit Einträgen aus einem Körper K, zum Beispiel die reellen oder komplexen Zahlen, ist genau dann invertierbar, wenn eine der folgenden äquivalenten Bedingungen erfüllt ist: An (n×n) matrix A with entries from a field K, for example the real or complex numbers, is invertible if and only if one of the following equivalent conditions is met:
・Der Rang der Matrix A ist gleich n ・The rank of the matrix A is equal to n
Generalization There are different generalizations of the concept of rank to matrices over arbitrary rings, where column rank, row rank, dimension of column space, and dimension of row space of a matrix may be different from the others or may not exist. Thinking of matrices as tensors, the tensor rank generalizes to arbitrary tensors; for tensors of order greater than 2 (matrices are order 2 tensors), rank is very hard to compute, unlike for matrices. There is a notion of rank for smooth maps between smooth manifolds. It is equal to the linear rank of the derivative. (google訳) 一般化 任意のリング上の行列に対するランクの概念にはさまざまな一般化があり、行列の列ランク、行ランク、列空間の次元、行空間の次元は他のものと異なる場合や存在しない場合があります。 行列をテンソルとして考えると、テンソルランクは任意のテンソルに一般化されます。 2 より大きい次数のテンソル (行列は次数 2 のテンソル) の場合、行列の場合とは異なり、ランクを計算するのは非常に困難です。 滑らかな多様体間の滑らかなマップにはランクの概念があります。これは導関数の線形ランクに等しくなります。
Matrices as tensors Matrix rank should not be confused with tensor order, which is called tensor rank. Tensor order is the number of indices required to write a tensor, and thus matrices all have tensor order 2. More precisely, matrices are tensors of type (1,1), having one row index and one column index, also called covariant order 1 and contravariant order 1; see Tensor (intrinsic definition) for details.
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Kurokawa, Nobushige American Mathematical Society K MR Author ID 108310 Earliest Indexed Publication 1978 Total Publications 129 Total Related Publications 1 Total Reviews 0 Total Citations 1,068 in 471 publications Unique Citing Authors 393
Kurokawa, Nobushige American Mathematical Society K MR Author ID 108310 Earliest Indexed Publication 1978 Total Publications 129 Total Related Publications 1 Total Reviews 0 Total Citations 1,071 in 472 publications Unique Citing Authors 397
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