Friday, June 25, 2021, 16:30 (Bucharest time), on Zoom A presentation given at the Topology Seminar. Speaker: Alexander Suciu (Northeastern University) Title: Algebra and topology of group extensions Abstract: I will present a study of the lower central series, the Alexander invariants, and the cohomology jump loci of groups arising as extensions with trivial monodromyContinue reading “Topology Seminar: Algebra and topology of group extensions”

# Category Archives: Topology Seminar

## Topology Seminar: Topology of complex projective hypersurfaces

Friday, June 18, 2021, 17:00 (Bucharest time), on Zoom A presentation given at the Topology Seminar. Speaker: Laurentiu Maxim (University of Wisconsin-Madison and IMAR) Title: Topology of complex projective hypersurfaces Abstract: I will overview old and new results which show how the presence of singularities affects the topology of complex projective hypersurfaces. Contact person: RaduContinue reading “Topology Seminar: Topology of complex projective hypersurfaces”

## Topology Seminar: Tropical upper bounds for the BNSR invariants

Friday, May 21, 2021, 16:30 (Bucharest time), on Zoom A presentation given at the Topology Seminar. The Zoom link is going to be announced next week by mail. Speaker: Alex Suciu (Northeastern University) Title: Tropical upper bounds for the BNSR invariants Abstract: The Bieri-Neumann-Strebel-Renz invariants are the vanishing loci for the Novikov-Sikorav homology of aContinue reading “Topology Seminar: Tropical upper bounds for the BNSR invariants”

## Topology Seminar: Lower central series of braid-like groups II

The IMAR Topology Seminar. Friday, January 29, 2021, 11:00 am, on Zoom platform For the zoom link please contact Radu Popescu (radu.popescu@imar.ro). Speaker: Martin Palmer Anghel (IMAR) Title: Lower central series of braid-like groups, II Abstract: One of the most basic objects one needs to understand when studying the structure of a group G isContinue reading “Topology Seminar: Lower central series of braid-like groups II”

## Topology Seminar: Lower central series of braid-like groups I

The IMAR Topology Seminar. Friday, January 22, 2021, 11:00 am, on Zoom platform For the zoom link please contact Radu Popescu (radu.popescu@imar.ro). Speaker: Martin Palmer Anghel (IMAR) Title: Lower central series of braid-like groups, I Abstract: One of the most basic objects one needs to understand when studying the structure of a group G isContinue reading “Topology Seminar: Lower central series of braid-like groups I”

## Topology Seminar: Groups related to mapping class groups of infinite type surfaces

The IMAR Topology Seminar Friday, December 11th, 2020, 11:00 Speaker: Louis Funar (CNRS-Universite Grenoble Alpes) Title: Groups related to mapping class groups of infinite type surfaces Abstract: The group of C^1 diffeomorphisms of sparse Cantor subsets of a manifold are countable and discrete. We can obtain this way Thompson’s groups and Brin’s higher dimensional generalizations.Continue reading “Topology Seminar: Groups related to mapping class groups of infinite type surfaces”

## Topology Seminar: Braided surfaces and their characteristic maps

The IMAR Topology Seminar Friday, December 4th, 2020, 11:00 Speaker: Louis Funar (CNRS-Universite Grenoble Alpes) Title: Braided surfaces and their characteristic maps Abstract: Our aim is to show that branched coverings of surfaces of large enough genus arise as characteristic maps of braided surfaces. In the reverse direction we show that any nonabelian surface groupContinue reading “Topology Seminar: Braided surfaces and their characteristic maps”

## Topology Seminar: Generalized Dehn twists on surfaces and surgeries in 3-manifolds

The IMAR Topology Seminar Tuesday, November 24, 2020, 11:00 Title: Generalized Dehn twists on surfaces and surgeries in 3-manifolds Abstract: (Joint work with Yusuke Kuno.) Given an oriented surface S and a simple closed curve C in S, the “Dehn twist” along C is the homeomorphism of S defined by “twisting” S around C byContinue reading “Topology Seminar: Generalized Dehn twists on surfaces and surgeries in 3-manifolds”

## Topology Seminar: Homology of configuration-section spaces

The IMAR Topology Seminar Friday, October 30, 2020, 11:00 -12:30 Title: Homology of configuration-section spaces Speaker: Martin Palmer-Anghel (IMAR) For the skype link please contact the speaker. Related: https://imaronline.wordpress.com/2020/10/16/purdue-topology-seminar-homology-of-configuration-section-spaces/

## Topology Seminar: U_q(sl(2)) quantum invariants unified through a state sum of Lagrangian intersections

The IMAR Topology Seminar will start next Friday October 23, 2020, 11:00 -12:30 Title: U_q(sl(2)) quantum invariants unified through a state sum of Lagrangian intersections Speaker: Cristina Palmer Anghel (IMAR) Unfortunately we will still meet on skype. For the skype link please contact the speaker.