Categoria:
Altro (categoria non censita)
Categoria non censita:
Ciclo di seminari BeyondCY3
Data e ora inizio evento:
Data e ora fine evento:
Aula:
Aula F
Sede:
Dipartimento di Matematica, Sapienza Università di Roma
Speaker:
Viktor Majewski (Universität Hamburg)
By the seminal work of Joyce on the construction of compact exceptional holonomy metrics, it is known that exceptional holonomy orbifolds naturally arise on the boundary of the corresponding moduli spaces. In this talk, we discuss a general resolution scheme for exceptional holonomy orbifolds in the case of Spin(7)-metrics. We introduce smooth Gromov–Hausdorff resolutions as the appropriate notion of exceptional holonomy orbifold resolutions. We identify the necessary geometric data required to construct adiabatic torsion-free Spin(7) orbifold resolutions and prove that, under the vanishing of an obstruction arising from string cohomology, these adiabatic torsion-free Spin(7) reso-
lutions can be deformed to genuine torsion-free Spin(7) metrics. This framework recovers Joyce’s generalized Kummer construction as well as the Joyce-Karigiannis construction
of resolutions of ”mild” G2 orbifolds. Finally, we present new compact examples of Spin(7)-manifolds, including a family exhibiting a neck-stretching phenomenon.
The talk is part of a series of lectures on the geometry of Riemannian manifolds with holonomy Spin(7) during the week Nov 24-28. The event is part of the activities of the FIS2 project BeyondCY3. More information available at: https://sites.google.com/uniroma1.it/lfoscolo/fis2-beyondcy3/events

