
Hopf algebras for matroids over hyperfields.
Preprint, joint with Chris Eppolito and Jaiung Jun.


The Hopf algebra of skew shapes, torsion sheaves on A^n/F_1, and ideals in Hall algebras of monoid representations.
Preprint.


Twisted modules and coinvariants for commutative vertex algebras of jet schemes
Preprint.


Quasicoherent sheaves on projective schemes over F_1
joint with Oliver Lorscheid. Journal of Pure and Applied Algebra 222 (2018), 13371354


Cech cohomology over F_{1^2}
joint with Jaret Flores and Oliver Lorscheid. To appear in J. Algebra


On the Hall Algebra of Semigroup Representations over F_1
Math. Z. 276 (2014), no. 12, 371386.


On the Hall Algebra of Coherent Sheaves on P^1 over F_1
in Journal for Pure and Applied Algebra 216 no. 2 (2012).


PreLie Algebras and Incidence Categories of Rooted Trees
Preprint


Representations of Quivers over F_1
IMRN (2012) Vol. 2012 no. 10, 23772404.


Incidence categories
Journal for Pure and Applied Algebra (215) 4 2011.


Colored trees and noncommutative symmetric functions
Electronic Journal of Combinatorics (17) 1 2010.


Hecke correspondences and Feynman graphs
Comm. in Number Theory and Physics (4) 2010.


Feynman graphs, rooted trees, and RingelHall algebras
Comm. Math. Phys. (289) 2009.
joint with Kobi Kremnizer


On the structure and representations of the insertionelimination Lie algebra
Lett. Math. Phys. (84) 2008.


Supersymmetry of the chiral de Rham complex
Compositio Math. (244) 2008.
joint with David BenZvi and Reimundo Heluani


Chiral de Rham complex and orbifolds
Journal of Algebraic Geometry (16) 2007
joint with Edward Frenkel


Discrete torsion, orbifold elliptic genera, and the chiral de Rham complex
Pure Appl. Math. Quart. (2) 2006 (special issue in honor of R. Macpherson).
joint with Anatoly Libgober


Orbifold conformal blocks and the stack of pointed Gcovers
J. Geom. Phys. , (56) 2006.


A first glimpse at the minimal model program
Snowbird lectures in algebraic geometry, Contemp. Math. 388, Amer. Math. Soc. 2005.
joint with Charles Cadman, Izzet Coskun et. al.


Twisted modules over vertex algebras on algebraic curves
Adv. Math. (187) 2004.
joint with Edward Frenkel


Wakimoto modules for twisted affine algebras
Math. Res. Lett. 9 (2002).


Algebraic curves, twisted vertex operators, and Prym varieties.
Ph. D. thesis  UC Berkeley 2002.


Photometric variability of P. Cygni 19851993
Astronomy and Astrophysics Suppl., (117) 1996.
joint with A. Attard and J. R. Percy


P. Cygni : Many periods or none
JAAVSO , (23) 2 1995, 140143.
joint with A. Attard and J. R. Percy
