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bio website math.berkeley.edu/~ianagol
location Berkeley
age 44
visits member for 5 years, 5 months
seen 37 mins ago

I'm a professor at UC Berkeley working predominantly in the field of low-dimensional topology.


22h
comment Classes of knots that have known Bridge spectra
Have a look at the blog post: ldtopology.wordpress.com/2013/02/16/the-bridge-spectrum
1d
comment Classes of knots that have known Bridge spectra
Tomova's result holds for any knot for which the bridge number is the tunnel number $+1$. This holds, for example, for the 2-bridge knots, and 3-bridge knots which are not tunnel number 1, so e.g. not strongly invertible.
1d
comment Knot theory question: bridge number vs. min generators of fundamental group of complement
Chris Cornwell obtained lower bounds on the meridional rank of certain pretzel knots, showing they are equal to the bridge number: arxiv.org/abs/1303.4943
Mar
26
awarded  Popular Question
Mar
26
awarded  Nice Question
Mar
24
answered arc length of a knot in the solid torus
Mar
18
comment hyperbolic metrics
This is true essentially by the Schwarz lemma. en.wikipedia.org/wiki/Schwarz_lemma
Mar
18
answered Geometric intersection with incompressible surfaces
Mar
17
answered What are known examples of a 3-manifold $Y$ embedded into $Y'\times I$ where $Y'$ is another 3-manifold?
Mar
16
revised Is there a non right-orderable torsion-free factor of the Braid group on 3 strands?
added 10 characters in body
Mar
16
comment Is there a non right-orderable torsion-free factor of the Braid group on 3 strands?
$\mathbb{QP}^1$ - I changed the notation, since this is probably only used by 3-manifold topologists.
Mar
16
answered Is there a non right-orderable torsion-free factor of the Braid group on 3 strands?
Mar
1
comment What is the growth of the rank of a power of a finite simple group?
One may find this article here: tau.ac.il/~jarden/Articles/paper68.pdf
Mar
1
comment What is the growth of the rank of a power of a finite simple group?
Essentially a duplicate of this question:mathoverflow.net/questions/187736/…
Mar
1
comment What is the growth of the rank of a power of a finite simple group?
possible duplicate of Powers of finite simple groups
Feb
27
comment Oriented knot complement conjecture for fibered knots
I suppose then one knows that 0-framed surgery is fibered (with non-zero genus), which implies it has non-trivial Floer homology (as opposed to $S^2\times S^1$. So the Floer exact triangle might impose some restrictions.
Feb
27
comment Residual finiteness: why do we care?
Residual finiteness (or rather a strengthening) was used by Friedl and Vidussi to prove: a closed 3-manifold x S^1 is symplectic iff the 3-manifold fibers over the circle. As for hyperbolic groups, there are various equivalent conditions to residual finiteness, such as every hyperbolic group has a finite-index torsion-free subgroup. This may be of interest, for example, to understand cohomological dimension, or to get rid of finite center.
Feb
19
comment Max flow, min cut on manifolds
I think you're searching for the concept of a calibrated manifold. en.wikipedia.org/wiki/Calibrated_geometry
Feb
17
awarded  Enlightened
Feb
17
awarded  Nice Answer