Moonshine theory | Lattice points | Sporadic groups | Quadratic forms

Leech lattice

In mathematics, the Leech lattice is an even unimodular lattice Λ24 in 24-dimensional Euclidean space, which is one of the best models for the kissing number problem. It was discovered by John Leech. It may also have been discovered (but not published) by Ernst Witt in 1940. (Wikipedia).

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How to construct the Leech lattice

This lecture describes an astonishingly simple construction of the Leech lattice in 24 dimensions, found by John Conway and Neal Sloane. This is an experimental joint video with @Lyam Boylan (https://www.tiktok.com/@yamsox/video/7057530890381053189) who added the animation, the thumbnai

From playlist Math talks

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History of science 7: Did Witt discover the Leech lattice?

In about 1970 the German mathematician Witt claimed to have discovered the Leech lattice many years before Leech. This video explains what the Leech lattice is and examines the evidence for Witt's claim. Lieven Lebruyn discussed this question on his blog: http://www.neverendingbooks.org/w

From playlist History of science

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Lattice Structures in Ionic Solids

We've learned a lot about covalent compounds, but we haven't talked quite as much about ionic compounds in their solid state. These will adopt a highly ordered and repeating lattice structure, but the geometry of the lattice depends entirely on the types of ions and their ratio in the chem

From playlist General Chemistry

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Lattice relations + Hermite normal form|Abstract Algebra Math Foundations 224 | NJ Wildberger

We introduce lattices and integral linear spans of vexels. These are remarkably flexible, common and useful algebraic objects, and they are the direct integral analogs of vector spaces. To understand the structure of a given lattice, the algorithm to compute a Hermite normal form basis is

From playlist Math Foundations

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Mod-01 Lec-5ex Diffraction Methods For Crystal Structures - Worked Examples

Condensed Matter Physics by Prof. G. Rangarajan, Department of Physics, IIT Madras. For more details on NPTEL visit http://nptel.iitm.ac.in

From playlist NPTEL: Condensed Matter Physics - CosmoLearning.com Physics Course

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MF150: What exactly is a set? | Data Structures in Mathematics Math Foundations | NJ Wildberger

What exactly is a set?? This is a crucial question in the modern foundations of mathematics. Here we begin an examination of this thorny issue, first by discussing the usual English usage of the term, as well as alternate terms, such as collection, aggregate, bunch, class, menagerie etc th

From playlist Math Foundations

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Quotient group example

Now that we know what a quotient group is, let's take a look at an example to cement our understanding of the concepts involved.

From playlist Abstract algebra

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Dihedral Group (Abstract Algebra)

The Dihedral Group is a classic finite group from abstract algebra. It is a non abelian groups (non commutative), and it is the group of symmetries of a regular polygon. This group is easy to work with computationally, and provides a great example of one connection between groups and geo

From playlist Abstract Algebra

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Genesis of vertex algebras

This is a historical talk giving my recollections of how vertex algebras were discovered. It was requested by Michael Penn for his series of videos on vertex algebras https://www.youtube.com/playlist?list=PL22w63XsKjqyx2FFUywi_mz91Jtih52yX

From playlist Math talks

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The Genesis of Vertex Algebras

We have a guest for this very special video. Richard Borcherds (Berkeley) has contributed a video regarding the history of vertex algebras. This video was also posted on his channel and is included here as well with permission and to increase its reach. Subscribe to his channel: https:/

From playlist Vertex Operator Algebras

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Tathagata Basak: A monstrous(?) complex hyperbolic orbifold

I will report on progress with Daniel Allcock on the ”Monstrous Proposal”, namely the conjecture: Complex hyperbolic 13-space, modulo a particular discrete group, and with orbifold structure changed in a simple way, has fundamental group equal to (MxM)(semidirect)2, where M is the Monster

From playlist Topology

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Modular forms: Theta functions in higher dimensions

This lecture is part of an online graduate course on modular forms. We study theta functions of even unimodular lattices, such as the root lattice of the E8 exceptional Lie algebra. As examples we show that one cannot "her the shape of a drum", and calculate the number of minimal vectors

From playlist Modular forms

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Sphere packings in 8 dimensions (after Maryna Viazovska)

The is a math talk about the best possible sphere packing in 8 dimensions. It was an open problem for many years to show that the best 8-dimensional sphere packing is given by the E8 lattice. We describe the solution to this found by Maryna Viazovska, building on work of Henry Cohn and Noa

From playlist Math talks

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Sporadic groups

This is an informal talk on sporadic groups given to the Archimedeans (the Cambridge undergraduate mathematical society). It discusses the classification of finite simple groups and some of the sporadic groups, and finishes by briefly describing monstrous moonshine. For other Archimedeans

From playlist Math talks

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Moonshine - 2 by Suresh Govindarajan

DATE & TIME 05 November 2016 to 14 November 2016 VENUE Ramanujan Lecture Hall, ICTS Bangalore Computational techniques are of great help in dealing with substantial, otherwise intractable examples, possibly leading to further structural insights and the detection of patterns in many abstra

From playlist Group Theory and Computational Methods

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Isometry groups of the projective line (I) | Rational Geometry Math Foundations 138 | NJ Wildberger

The projective line can be given a Euclidean structure, just as the affine line can, but it is a bit more complicated. The algebraic structure of this projective line supports some symmetries. Symmetry in mathematics is often most efficiently encoded with the idea of a group--a technical t

From playlist Math Foundations

Related pages

Kissing number | Sporadic group | Suzuki sporadic group | Monster group | Modular group | Upper half-plane | Dynkin diagram | Coding theory | Orbifold | Monstrous moonshine | Spherical code | Ramanujan tau function | Mathieu group M12 | Sphere packing | Conway group | Unimodular lattice | Hexagonal lattice | E8 lattice | Icosian | John Horton Conway | Generator matrix | Modular form | Root system | Ternary Golay code | Determinant | Hamming code | Quotient group | Torus | Hadamard code | Monster vertex algebra | Reflection group | Mathematics | Coxeter–Todd lattice | Binary Golay code | Barnes–Wall lattice | Integer | Janko group | Octonion | II25,1 | Hexagonal tiling | Euclidean space | Mathieu group M24 | Tammes problem | Holomorphic function | Integer lattice | Automorphism group | Griess algebra | Theta function | Édouard Lucas | Square number | Matrix (mathematics) | Hadamard matrix | Eisenstein series | Divisor function | Niemeier lattice