In mathematics, a twisted sheaf is a variant of a coherent sheaf. Precisely, it is specified by: an open covering in the étale topology Ui, coherent sheaves Fi over Ui, a Čech 2-cocycle θ on the covering Ui as well as the isomorphisms satisfying * , * * The notion of twisted sheaves was introduced by Jean Giraud. The above definition due to Căldăraru is down-to-earth but is equivalent to a more sophisticated definition in terms of gerbe; see § 2.1.3 of. (Wikipedia).
Who Gives a Sheaf? Part 1: A First Example
We take a first look at (pre-)sheaves, as being inspired from first year calculus.
From playlist Who Gives a Sheaf?
#Cycloid: A curve traced by a point on a circle rolling in a straight line. (A preview of this Sunday's video.)
From playlist Miscellaneous
Free ebook http://tinyurl.com/EngMathYT A basic introduction to the curl of a vector field - one of the basic operations of vector calculus. I show how to calculate the curl and discuss its relationship with rotation and circulation density. Many examples are presented.
From playlist Engineering Mathematics
Vector Calculus: Understanding Curl
Some formal and informal intuition regarding curl, a vector calculus concept.
From playlist Summer of Math Exposition Youtube Videos
A variation on an Ulam Spiral: a Sacks Spiral
Simplicity making complexity. In one word: Emergence. Using the same process as my Ulam Spiral video, https://youtu.be/JjBnLz0SF3A but this time in a Sacks Spiral, https://youtu.be/iFuR97YcSLM?t=6m3s Enjoy. Animation made with FMS Logo.
From playlist Artsy things
Cyclic Quadrilateral: Proof Hint!
Link: https://www.geogebra.org/m/KYdypjws
From playlist Geometry: Dynamic Interactives!
Who Gives a Sheaf? Part 3: Mighty Morph'n Morphisms
In this video we discuss the definition of a morphism of sheaves.
From playlist Who Gives a Sheaf?
Cyclic Quadrilaterals and Parallel Lines in Circles
Watch more videos on http://www.brightstorm.com/math/geometry SUBSCRIBE FOR All OUR VIDEOS! https://www.youtube.com/subscription_center?add_user=brightstorm2 VISIT BRIGHTSTORM.com FOR TONS OF VIDEO TUTORIALS AND OTHER FEATURES! http://www.brightstorm.com/ LET'S CONNECT! Facebook ► https
From playlist Geometry
Simple intro to the curl of a vector field and how to calculate it. The curl is one of the basic operations of vector calculus.
From playlist Engineering Mathematics
Geometric Langlands correspondence via quantization in positive characteristic - Roman Travkin
Geometric Langlands correspondence via quantization in positive characteristic Speaker: Roman Travkin, Member, School of Mathematics Time/Room: 2:30pm - 2:45pm/S-101 More videos on http://video.ias.edu
From playlist Mathematics
Perfect points on abelian varieties in positive characteristic. - Rössler - Workshop 2 - CEB T2 2019
Damian Rössler (University of Oxford) / 24.06.2019 Perfect points on abelian varieties in positive characteristic. Let K be the function field over a smooth curve over a perfect field of characteristic p 0. Let Kperf be the maximal purely inseparable extension of K. Let A be an abelian
From playlist 2019 - T2 - Reinventing rational points
Marc Levine: The rational motivic sphere spectrum and motivic Serre finiteness
Find this video and other talks given by worldwide mathematicians on CIRM's Audiovisual Mathematics Library: http://library.cirm-math.fr. And discover all its functionalities: - Chapter markers and keywords to watch the parts of your choice in the video - Videos enriched with abstracts, b
From playlist SPECIAL 7th European congress of Mathematics Berlin 2016.
Joel Friedman - Sheaves on Graphs, L^2 Betti Numbers, and Applications.
Joel Friedman (University of British Columbia, Canada) Sheaf theory and (co)homology, in the generality developed by Grothendieck et al., seems to hold great promise for applications in discrete mathematics. We shall describe sheaves on graphs and their applications to (1) solving the
From playlist T1-2014 : Random walks and asymptopic geometry of groups.
Brauer groups, Severi-Brauer schemes, Azumaya algebras, twisted sheaves
From playlist Étale cohomology and the Weil conjectures
Marc Levine: Refined enumerative geometry (Lecture 1)
The lecture was held within the framework of the Hausdorff Trimester Program: K-Theory and Related Fields. Marc Levine: Refined enumerative geometry Abstract: Lecture 1: Milnor-Witt sheaves, motivic homotopy theory and Chow-Witt groups We review the Hoplins-Morel construction of the Miln
From playlist HIM Lectures: Trimester Program "K-Theory and Related Fields"
Finiteness, Z_l-sheaves
From playlist Étale cohomology and the Weil conjectures
Kevin Costello - A twisted form of the ADS/CFT correspondence
Kevin COSTELLO (Northwestern Univ., Evanston, USA)
From playlist Algèbre, Géométrie et Physique : une conférence en l'honneur
Proper base change continued, compactly supported cohomology, cohomology with supports, Gysin sequences and purity
From playlist Étale cohomology and the Weil conjectures
Physics - Advanced E&M: Ch 1 Math Concepts (12 of 55) What is the Curl of a Vector?
Visit http://ilectureonline.com for more math and science lectures! In this video I will explain, develop the equation, and give an example of the curl of a vector. Next video in this series can be seen at: https://youtu.be/BvO6FuRJHp4
From playlist PHYSICS 67 ADVANCED ELECTRICITY & MAGNETISM
Schemes 28: Examples of quasicoherent sheaves
This lecture is part of an online algebraic geometry course on schemes, based on chapter II of "Algebraic geometry" by Hartshorne. We give some examples of quasicoherent sheaves over affine schemes, and define vector bundles, line bundles, and the Picard group.
From playlist Algebraic geometry II: Schemes