Arithmetic geometry

Anabelian geometry

Anabelian geometry is a theory in number theory which describes the way in which the algebraic fundamental group G of a certain arithmetic variety X, or some related geometric object, can help to restore X. The first results for number fields and their absolute Galois groups were obtained by Jürgen Neukirch, Masatoshi Gündüz Ikeda, Kenkichi Iwasawa, and Kôji Uchida (Neukirch–Uchida theorem, 1969) prior to conjectures made about hyperbolic curves over number fields by Alexander Grothendieck. As introduced in Esquisse d'un Programme the latter were about how topological homomorphisms between two arithmetic fundamental groups of two hyperbolic curves over number fields correspond to maps between the curves. These Grothendieck conjectures were partially solved by Hiroaki Nakamura and Akio Tamagawa, while complete proofs were given by Shinichi Mochizuki. Anabelian geometry can be viewed as one of the three generalizations of class field theory. Unlike two other generalizations — abelian higher class field theory and representation theoretic Langlands program — anabelian geometry is non-abelian and highly non-linear. (Wikipedia).

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Anabelian Geometry - Absolute Anabelian Geometry and the Reconstruction of the Base Field

This video describes one of the key features of absolute anabelian geometry. One is able to interpret the map Pi_X \to G_K just from Pi_X itself! https://twitter.com/dupuytaylor

From playlist Anabelian Geometry

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Anabelian Geometry - The Section Injection

Tamagawa's 1999 IMRN paper has a nice proof. Read this paper. Twitter: https://twitter.com/dupuytaylor

From playlist Anabelian Geometry

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Anabelian Geometry - part 0 - Overview of the Papers

Here we describe what papers are involved here. There are two notable mentions which we have not described. Twitter: @DupuyTaylor

From playlist Anabelian Geometry

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Anabelian Geometry - Inertia and Decomposition Groups (Part 1)

We discuss the statements about the recovery of inertia and decomposition groups of cusps. We will give proofs in the number field case of some statements. Proofs for finite extensions of QQ_p appear later. Twitter: @DupuyTaylor

From playlist Anabelian Geometry

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Anabelian Geometry - Kummer Classes

To functions f we associate cohomology classes. Using galois sections we can evaluate these functions. Recovering the Kummer classes of the jacobi theta function

From playlist Anabelian Geometry

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Parabola Terms

Introduction to the terms locus, focus, directrix, line of symmetry, vertex, maximum and minimum

From playlist Geometry

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Inertia and Decomposition Groups (part 3)

Here we do the local case. Twitter: @DupuyTaylor

From playlist Anabelian Geometry

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Divine Proportions: Rational Trigonometry to Universal Geometry

I discuss my book Divine Proportions: Rational Trigonometry to Universal Geometry, which gives a novel way of thinking not only about trigonometry, but also Euclidean geometry. It also lays the ground work for a more rational and logical approach to other geometries, including hyperbolic g

From playlist MathSeminars

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David Roberts, Hurwitz Belyi maps

VaNTAGe seminar, October 12, 2021 License: CC-BY-NC-SA

From playlist Belyi maps and Hurwitz spaces

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Toy Ind3 - Part 03 - Anabelian Geometry and the Case of a Single Log Link

Here we briefly discuss Corollary 1.10 of Absolute Anabelian Geometry 3. This result is used in the Definition 1.1 of IUT3 which is the case of a log-link. Using this setup we are able to give a structure result (omitted in the body of IUT) that is key to deriving the log-shell upper bound

From playlist Toy Ind3

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CTNT 2022 - Grothendieck’s section set and the Lawrence–Venkatesh method (by Alex Betts)

This video is one of the special guess talks or conference talks that took place during CTNT 2022, the Connecticut Summer School and Conference in Number Theory. Note: not every special guest lecture or conference lecture was recorded. More about CTNT: https://ctnt-summer.math.uconn.edu/

From playlist CTNT 2022 - Conference lectures and special guest lectures

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Math Talk! Taylor Dupuy, professor of mathematics, (differential) algebraic geometry and IUTT.

A conversation with Dr. Dupuy about differential algebraic geometry, the abc-conjecture and IUTT, the field with one element, Clifford algebras, and more! Dr. Dupuy's channel: https://www.youtube.com/channel/UCHWnZ1NtJ4WvE5AHmNVXziw Homepage: https://www.uvm.edu/~tdupuy/ AWS: https://

From playlist Math Talk!

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Introduction to Projective Geometry (Part 1)

The first video in a series on projective geometry. We discuss the motivation for studying projective planes, and list the axioms of affine planes.

From playlist Introduction to Projective Geometry

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The circle and projective homogeneous coordinates (cont.) | Universal Hyperbolic Geometry 7b

Universal hyperbolic geometry is based on projective geometry. This video introduces this important subject, which these days is sadly absent from most undergrad/college curriculums. We adopt the 19th century view of a projective space as the space of one-dimensional subspaces of an affine

From playlist Universal Hyperbolic Geometry

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Hyperbola 3D Animation | Objective conic hyperbola | Digital Learning

Hyperbola 3D Animation In mathematics, a hyperbola is a type of smooth curve lying in a plane, defined by its geometric properties or by equations for which it is the solution set. A hyperbola has two pieces, called connected components or branches, that are mirror images of each other an

From playlist Maths Topics

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The p-adic Logarithm - Part 03 - Log Shells

Here are the "log-shells" which originated (I think) in Mochizuki's Topics in Absolute Anabelian Geometry 3. They can be interpreted using absolute Galois groups of local fields and appear in Mochizuki's inequality.

From playlist p-adic log

Related pages

Inter-universal Teichmüller theory | Neukirch–Uchida theorem | Local field | Class field theory | P-adic Teichmüller theory | Alexander Grothendieck | Affine curvature | Frobenioid | Kenkichi Iwasawa | Belyi's theorem | Étale fundamental group | Projective line | Langlands program | Number theory | Algebraic curve | Fiber functor | Esquisse d'un Programme | Arithmetic variety | Profinite group | Jürgen Neukirch | Cross-ratio