[phys4phys] Group for Gravitation, Particle and Fields seminar, Friday, 29 March 2024

[dgocanin]

Dear colleagues,

You are cordially invited to the seminar of the Group for Gravitation, 
Particles and Fields, which will be held on Friday, 29 March 2024, at 
11:00 at the Institute of Physics Belgrade, lecture hall 360.

The talk entitled

2-groups and crossed modules: Classification and algorithm for 
constructing non-trivial ones

will be given by Petar Petrašinović (Faculty of Physics University of 
Belgrade).

Abstract: The 2-groups are category theory generalisations of the usual 
groups. They are equivalent to crossed modules, consisting of two 
groups, G and H, the homomorphism ∂ from H to G and the action ▷ from G 
to H. One can construct a gauge theory of gravity on a 4-manifold based 
on crossed modules (like the BFCG theory for the Poincaré 2-group). 
Besides the usual group axioms, crossed modules must satisfy additional 
axioms. For this reason, they are much more rigid structures and more 
difficult to construct. There are some typical examples, but they are 
very rare and in which either ∂ or ▷ is trivial. In this seminar, I will 
discuss the properties of their linear structure-differential crossed 
modules. A possible way to classify these modules will be shown. 
Together with the classification, a corresponding algorithm for 
constructing differential cross modules with non-trivial ∂ and ▷ will be 
presented, which constructs them either for given groups G and H or for 
given ∂ and ▷.


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Time: March 29, 2024 11:00 Belgrade

Institute of Physics Belgrade, lecture hall 360, 2nd floor

BigBlueButton platform link: 
https://gravityserver.ipb.ac.rs/b/mar-ae0-f4q-qww

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Best regards,
Dragoljub