


Postdoctorant, Université de Genève.


Université de Genève
Mathématiques
Villa Battelle
1227 Carouge, Suisse
Email: Jens.Forsgaard at unige.ch

Photos taken by Elis Forsgård, Lionel Lang, and Hilary Page.

My CV is available here.
Last updated on 14 October 2017.


Research
I am interested in geometry of zeros, tropical geomtry and (co)amoebas, toric geometry and polytopes,
and Ahypergeometric functions.
I am currently a Postdoctorant (Postdoctoral Scholar) at
Université de Genève,
where my mentor is Professor Grigory Mikhalkin.
Before, I was a Visiting Assistant Professor at
Texas A&M University,
mentored by Professor Laura Felicia Matusevich.
I obtained my Ph.D. at
Stockholm University under the supervision
of Professor Boris Shapiro. I was a student of Mikael Passare at the time of his death.


Recent preprints
 The Lattice of Amoebas, with T. de Wolff
arXiv:1711.02705.
 Defective dual varieties for real spectra,
to appear in Journal of Algebraic Combinatorics,
arXiv:1710.02434.
 New subexponential fewnomial hypersurface bounds,
with M. Nisse
and J. Maurice Rojas,
arXiv:1710.00481.
 On transformations of Ahypergeometric functions,
with L. F. Matusevich
and A. Sobieska,
to appear in Funkcialaj Ekvacioj,
arXiv:1703.03036.
 On the multivariate Fujiwara bound for exponential sums, submitted,
arXiv:1612.03738.
 Lopsided amoeba approximation,
with L. F. Matusevich,
N. Mehlhop, and
T. de Wolff,
to appear in Mathematics of Computation,
arXiv:1608.08663.
(An implementation can be found
here.)
 On dimer models and coamoebas,
to appear in Ann. Inst. Henri Poincaré D,
arXiv:1602.01826.
 Discriminant amoebas and lopsidedness, to appear in Journal of Commutative Algebra.


Published Papers
In reverse chronological order.
 Coamoebas of polynomials supported on circuits,
in Analysis Meets Geometry, The Mikael Passare Memorial Volume
(Andersson, Boman, Kiselman, Kurasov, and Sigurdsson, eds.),
Trends in Mathematics, Birkhäuser, Basel, 2017, pp. 191–212,
doi:10.1007/9783319524719_13,
arXiv:1601.05468.
 On the parametric behavior of Ahypergeometric series,
with C. Berkesch Zamaere
and L. F. Matusevich,
Trans. Amer. Math. Soc., in press,
doi:10.1090/tran/7071,
arXiv:1603.08954.
 A tropical analog of Descartes' rule of signs,
with D. Novikov
and B. Shapiro,
Int. Math. Res. Notices 2017 (2017), no. 12, 3726–3750,
doi:10.1093/imrn/rnw118, arXiv:1510.03257.
 Hypergeometric functions for projective toric curves,
with C. Berkesch Zamaere
and L. F. Matusevich,
Adv. Math. 300 (2016), 835–867,
doi:10.1016/j.aim.2016.03.032,
arXiv:1412.3957.
 Could Renè Descartes have known this?,
with B. Shapiro
and V. P. Kostov, Exp. Math. 24 (2015), no. 4, 438–448,
doi:10.1080/10586458.2015.1030051,
arXiv:1501.00856.
(1501_Descartes.nb.)
 On the order map for hypersurface coamoebas,
with P. Johansson, Ark. Mat. 53 (2015), no. 1, 79–104,
doi:10.1007/s115120130195y,
arXiv:1205.2014.
 Coamoebas and line arrangements in dimension two,
with P. Johansson, Math. Z. 278 (2014), no. 1–2, 25–38,
doi:10.1007/s0020901413039.
 Euler–Mellin integrals and Ahypergeometric functions,
with C. Berkesch and M. Passare,
Michigan Math. J. 63 (2014), no. 1, 101–123,
doi:10.1307/mmj/1395234361,
arXiv:1103.6273.


Other publications
 Coamoebas of bivariate multiaffine polynomials.
 Rullgård's wild guess is false.
 A Mathematica notebook for drawing coamoebas is
available here.
 Tropical aspects of real polynomials and hypergeometric functions,
doctoral thesis, Stockholm University, 2015.
Available here.
 On hypersurface coamoebas and integral representations of Ahypergeometric functions,
licentiate thesis, Stockholm University, 2012.
Available here.


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