John Christian Ottem

Department of Pure Mathematics and Mathematical Statistics
University of Cambridge
DPMMS, Wilberforce Road, Cambridge CB3 0WA, UK
Email: J.C.Ottem α

I am currently a postdoc in the DPMMS at the University of Cambridge and a Junior Research Fellow at King's College.

My mathematical interests include higher dimensional algebraic geometry, positivity of line bundles and subschemes, Calabi-Yau manifolds and
the moduli space of curves.


Nef cycles on some hyperkahler fourfolds. PDF
Curves disjoint from a nef divisor (with J. Lesieutre). PDF
On subvarieties with ample normal bundle. To appear in Journal of the European Mathematical Society PDF
Quartic spectrahedra (with K. Ranestad, B. Sturmfels, C. Vinzant) Math. Prog. B (2015). PDF
Birational geometry of hypersurfaces in products of projective spaces. Mathematische Zeitschrift 280 (2015), 135-148 PDF
Ample subvarieties and q-ample divisors. Advances in Mathematics 229 (2012), 2868-2887. PDF
Algebraic boundaries of Hilbert's SOS cones (with G. Blekherman, J. Hauenstein, K. Ranestad and B. Sturmfels). Compositio Mathematica 148 (2012). PDF
Partially ample line bundles on toric varieties. (with N. Broomhead and A. Prendergast-Smith). To appear in Glasgow Mathematical Journal (2015). PDF
Components of the Hilbert scheme of space curves on low-degree smooth surfaces (with J. O. Kleppe). International Journal of Mathematics Vol. 26, (2015) PDF
The Cox ring of a K3 surface of Picard number two. Journal of Pure and Applied Algebra 217 (2013), 709-715. PDF
On the Cox Ring of P^2 Blown Up in Points on a Line. Mathematica Scandinavica 9, (2011), 21-31. PDF

Some notes

`Positive vector bundles and cycles'. Summer school on positivity, Loughborough 2015. PDF
`Curves and their moduli'. Graduate course, spring 2014. PDF.