Hello everyone,
This week we are really excited to have Roman Aranda (virtually) coming down from Iowa to speak.
His title and abstract are below:
4-manifolds with small trisection genus Speaker: Roman Aranda, University of Iowa Time: Oct 28, 2020, 3:45 PM Room: Virtual meeting https://meet.google.com/frv-bgow-byi
Abstract: In 2016, D. Gay and R. Kirby proved that every closed 4-manifold can be decomposed as the union of three 4-dimensional simple pieces with triple intersection a closed orientable surface of genus g. This decomposition is called a trisection of genus g for M. In 2018, M. Chu and S. Tillmann gave a lower bound for the trisection genus of a closed 4-manifold in terms of the rank of its fundamental group. In this talk, we show that given a group G, there exists a 4-manifold M with fundamental group G with trisection genus achieving Chu-Tillmann’s lower bound. The proof uses techniques of knot theory in simple 3-manifolds.
___________________ Neil Hoffman
Hello everyone,
Sorry for the two emails.
First, I hope everyone is okay.
With campus closed tomorrow and internet down around Stillwater, I wanted to check in to see if people still could make seminar tomorrow. If we can get a good enough turnout, I am inclined to try to hold seminar tomorrow.
If possible, could you send an email back that you can make seminar tomorrow if it’s held?
I might have to assume that those that don’t respond are without internet, but if you are getting this on your phone because your home internet is down that would be helpful for me to know.
Best, Neil
___________________ Neil Hoffman
On Oct 27, 2020, at 3:31 PM, Hoffman, Neil neil.r.hoffman@okstate.edu wrote:
Hello everyone,
This week we are really excited to have Roman Aranda (virtually) coming down from Iowa to speak.
His title and abstract are below:
4-manifolds with small trisection genus Speaker: Roman Aranda, University of Iowa Time: Oct 28, 2020, 3:45 PM Room: Virtual meeting https://meet.google.com/frv-bgow-byi
Abstract: In 2016, D. Gay and R. Kirby proved that every closed 4-manifold can be decomposed as the union of three 4-dimensional simple pieces with triple intersection a closed orientable surface of genus g. This decomposition is called a trisection of genus g for M. In 2018, M. Chu and S. Tillmann gave a lower bound for the trisection genus of a closed 4-manifold in terms of the rank of its fundamental group. In this talk, we show that given a group G, there exists a 4-manifold M with fundamental group G with trisection genus achieving Chu-Tillmann’s lower bound. The proof uses techniques of knot theory in simple 3-manifolds.
___________________ Neil Hoffman
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Hoffman, Neil