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| I am an IRCSET-Marie Curie Inspire Postdoctoral Fellow. My current research project addresses questions relating to function fields of quadratic forms (see Research Interests for more details). I spent the first two years of this project working under the mentorship of Dr. Karim Becher at the University of Konstanz, and am currently completing the final phase under the mentorship of Dr. Thomas Unger at University College Dublin. |
| My research interests lie within the algebraic theory of quadratic forms. In addition, I am interested in the overlap between quadratic form theory and the theory of algebras with involution, cohomology theories and algebraic geometry.
A quadratic form, or homogeneous polynomial of degree two, is said to be isotropic if it has a non-trivial representation of zero, and is anisotropic otherwise. The hyperbolic plane H is the unique 2-dimensional isotropic (quadratic) form. By a theorem of Witt, every form q has a decomposition q = q_an + i(q) x H, where the integer i(q) and the anisotropic form q_an are uniquely determined.
(i) furthering the understanding of the isotropy/anisotropy of forms with respect to function field extensions, (ii) applying this understanding to resolve open problems in quadratic form theory (for example, invariant determination problems, as motivated above). |
O'Shea, J; (2012) 'Isotropy over function fields of Pfister forms'. Journal of Algebra, 361 :23-36. [DOI] [Details] |
O'Shea, J; (2011) 'Sums of squares in certain quaternion and octonion algebras'. Comptes Rendus Mathématique. Académie des Sciences. Paris, 349 :239-242. [DOI] [Details] |
O'Shea, J; (2010) 'Bounds on the levels of composition algebras'. Mathematical Proceedings of the Royal Irish Academy, 110 :21-30. [DOI] [Details] |
O'Shea, J,Van Geel, J; (2008) 'Levels and sublevels of composition algebras over p-adic function fields'. ARCHIV DER MATHEMATIK, 91 :31-43. [DOI] [Details] |
O'Shea, J; (2007) 'Levels and sublevels of composition algebras'. Indagationes Mathematicae-New Series, 18 :147-159. [DOI] [Details] |