Baldur Sigurðsson




I am currenly working as a postdoc at the math department of UNAM in Cuernavaca, Mexico.


I finished a BS degree at The University of Iceland () in 2008 and an MS degree at Eötvös Loránd Tudományegyetem (ELTE) in 2010. I finished my PhD at CEU under the supervision of András Némethi in December 2015. I also worked on normal surface singularities as part of the low dimensional topology team at the Alfréd Rényi Institute of Mathematics. until February 2016. From then, and until November 2018, I was a postdoc working with the singularity theory and algebraic geometry group at Basque Center for Applied Mathematics BCAM in Bilbao.


pdf Curriculum vitae.

Written content


arXiv pdf On ideal filtrations for Newton nondegenerate surface singularities, 2019.


arXiv pdf prrw Joint with Pablo Portilla Cuadrado, Mixed tête-à-tête twists as monodromies associated with holomorphic function germs, accepted for publication in Geometriae Dedicata.

arXiv pdf prrw The boundary of the Milnor fiber of the singularity 𝑓(π‘₯,𝑦)+𝑧𝑔(π‘₯,𝑦)=0. European Journal of Mathematics (2020) doi:10.1007/s40879-019-00393-w

arXiv pdf prrw Joint with András Némethi, The geometric genus of hypersurface singularities, J. Eur. Math. Soc. (JEMS) 18, No. 4, 825-851 (2016).

arXiv pdf prrw The Milnor fiber of the singularity f(x,y) + zg(x,y) = 0. Rev Mat Complut (2016) 29: 225. doi:10.1007/s13163-015-0179-5.


pdf The geometric genus of hypersurfaces, presented on the 13th International Workshop on Real and Complex Singularities Celebrating the 60th birthday of MarΓ­a del Carmen Romero Fuster July 27th - August 1st 2014.


pdf The geometric genus and the Seiberg-Witten invariant of Newton nondegenerate surface singularities.

pdf Slides presented during the defense.


C man A program for calculating invariants related to lattice cohomology.

GP A collection of functions related to numerical invariants of surface singularities written in PARI/GP. Includes an implementation of Oka's algorithm. Be warned that the function that calculates the Turaev torsion is flaky. I'll have to redo that whole thing, but until then, don't take it as absolute truth. In particular, the Seiberg-Witten invariant may be incorrect.

html A collection of small projects.

sage An implementation of plumbing graphs in sage. This is work in progress, but it will hopefully get accepted into the sage project soon. Some functionality is still lacking, and there are probably some errors in there, since it hasn't been tested much. This is where you come in!


html Here are some notes on various issues. I'm mostly collecting them here for myself, but maybe they are of help to others.


BCAM email

pgp public key gmail email