Articles (2001-2022)

On orbit closures of spherical subgroups in flag varieties
Comment. Math. Helv. 76 (2001), 263-299.

The virtual Poincaré polynomials of homogeneous spaces
(avec E. Peyre)
Compos. Math. 134 (2002), 319-335.

Positivity in the Grothendieck group of complex flag varieties
J. Algebra (special volume in honor of Claudio Procesi) 258 (2002), 137-159.

Group completions via Hilbert schemes
J. Algebraic Geom. 12 (2003), 605-626.

Multiplicity-free subvarieties of flag varieties
dans : Contemporary Math. 331, 13-23, Amer. Math. Soc., Providence, 2003.

The cone of effective one-cycles of certain G-varieties
dans : A Tribute to C. S. Seshadri, 180-198, Hindustan Book Agency, 2003.

A geometric approach to standard monomial theory
(avec V. Lakshmibai)
Represent. Theory 7 (2003), 651-680.

Stable reductive varieties I: Affine varieties
(avec V. Alexeev)
Invent. Math. 157 (2004), 227-274.

Stable reductive varieties II: Projective case
(avec V. Alexeev)
Adv. Math. 184 (2004), 380-408.

Toric degenerations of spherical varieties
(avec V. Alexeev)
Selecta Math. (N.S.) 10 (2004), 453-478.

Intersection cohomology of reductive varieties
(avec R. Joshua)
J. Eur. Math. Soc. 6 (2004), 465-481.

The equivariant cohomology ring of regular varieties
(avec J. B. Carrell)
Michigan Math. J. 52 (2004), 189-203.

Moduli of affine schemes with reductive group action
(avec V. Alexeev)
J. Algebraic Geom. 14 (2005), 83-117.

Vanishing of top equivariant Chern classes of regular embeddings
(avec I. Kausz)
Asian J. Math. 9 (2005), 489-496.

F-regularity of large Schubert varieties
(avec J. F. Thomsen)
Amer. J. Math. 128 (2006), 949-962.

Stable spherical varieties and their moduli
(avec V. Alexeev)
Int. Math. Res. Pap. IMRP 16 (2006), 1-57.

The total coordinate ring of a spherical variety
J. Algebra (special volume in honor of E.B. Vinberg) 313 (2007), 61-99.

Construction of equivariant vector bundles
dans : Algebraic groups and homogeneous spaces, 83-111, Narosa, New Dehli, 2007.

The structure of normal algebraic monoids
(avec A. Rittatore)
Semigroup Forum 74 (2007), 410-422.

Log homogeneous varieties
dans : Actas del XVI Coloquio Latinoamericano de Àlgebra, 1-39,
Revista Matemática Iberoamericana, Madrid, 2007.

Equivariant Chow ring and Chern classes of wonderful symmetric varieties of minimal rank
(avec R. Joshua)
Transform. Groups (special volume in honor of B. Kostant) 13 (2008), 471-493.

Local structure of algebraic monoids
Mosc. Math. J. 8 (2008), 1-21.

Anti-affine algebraic groups
J. Algebra 321 (2009), 934-952.

Vanishing theorems for Dolbeault cohomology of log homogeneous varieties
Tohoku Math. J. 61 (2009), 365-392.

Some basic results on actions of non-affine algebraic groups
Symmetry and Spaces: in honor of Gerry Schwarz,
Progr. Math. 278, 1-20, Birkäuser (2010).

Counting points of homogeneous varieties over finite fields
(avec E. Peyre)
J. Reine Angew. Math. 645 (2010), 105-124.

On the geometry of algebraic groups and homogeneous spaces,
J. Algebra 329 (2011), 52-71.

On automorphism groups of fiber bundles,
Publ. Math. Urug. 12 (2011), 39-66.

Homogeneous bundles over abelian varieties,
J. Ramanujan Math. Soc. 27 (2012), 91-118.

Notions of purity and the cohomology of quiver moduli,
(avec R. Joshua), Internat. J. Math. 23 (2012), no. 9.

Prime-to-p étale covers of algebraic groups,
(avec T. Szamuely), Bull. London Math. Soc. 45 (2013), 602-612.

The coherent cohomology ring of an algebraic group,
Algebr. Represent. Theory 16 (2013), 1449-1467.

On connected automorphism groups of algebraic varieties,
J. Ramanujan Math. Soc. 28A (Special Issue - 2013), 41-54.

Homogeneous projective bundles over abelian varieties,
Algebra Number Theory 7 (2013), 2475-2510.

On automorphisms and endomorphisms of projective varieties,
Automorphisms in Birational and Affine Geometry,
Springer Proc. Math. Stat. 79, 59-82, Springer, 2014.

On algebraic semigroups and monoids,
Algebraic Monoids, Group Embeddings, and Algebraic Combinatorics,
Fields Institute Communications 71, 1-54, Springer, 2014.

On algebraic semigroups and monoids, II,
Semigroup Forum 88 (2014), 250-272.

Algebraic semigroups are strongly π-regular
(avec L. E. Renner),
Algebraic Monoids, Group Embeddings, and Algebraic Combinatorics,
Fields Institute Communications 71, 55-59, Springer, 2014.

Which algebraic groups are Picard varieties?
Science China Mathematics 58 (2014), 461-478.

On extensions of algebraic groups with finite quotient,
Pacific J. Math. (Robert Steinberg Memorial Issue) 279 (2015), 135-153.

Minimal rational curves on wonderful group compactifications
(avec B. Fu), J. Éc. polytech. Math. 2 (2015), 153-170.

Symplectic resolutions for conical symplectic varieties
(avec B. Fu), Internat. Math. Res. Notices 12 (2015), 4335-4343.

On linearization of line bundles,
J. Math. Sci. Univ. Tokyo (Kodaira Centennial Issue) 22 (2015), 1-35.

Some structure theorems for algebraic groups,
Proc. Symp. Pure Math. 94 (2017), 53-125.

Algebraic group actions on normal varieties,
Trans. Moscow Math. Soc. 78 (2017), 85-107.

Epimorphic subgroups of algebraic groups,
Math. Res. Letters. 24 (2017), 1649-1665.

Log Kodaira dimension of homogeneous varieties (avec De-Qi Zhang),
Adv. Stud. Pure Math. 75 (2017), 1-6.

Commutative algebraic groups up to isogeny,
Documenta Math. 22 (2017), 679-725.

Commutative algebraic groups up to isogeny. II,
Contemp. Math. 705 (2018), 1-36.

Homological dimension of isogeny categories of commutative algebraic groups,
European Journal of Mathematics 5 (2019), 1107-1138.

On the fundamental groups of commutative algebraic groups,
Annales Henri Lebesgue 3 (2020), 1-34.

Homogeneous vector bundles over abelian varieties via representation theory,
Representation Theory 24 (2020), 85-114.

Very special algebraic groups (avec E. Peyre),
Comptes Rendus Mathématique 6 (2020), 713-719.

Some automorphism groups are linear algebraic,
Moscow Mathematical Journal 21 (2021), 453-466.

Homogeneous varieties under split solvable algebraic groups,
Indagationes Mathematicae (special issue to the memory of T. A. Springer) 32 (2021), 1139-1151.

(avec S. Senthamarai Kannan) Minimal rational curves on generalized Bott-Samelson varieties,
Compositio Mathematica 157 (2021), 122-153.

Homomorphisms of algebraic groups: representability and rigidity,
Michigan Mathematical Journal (special volume in honor of Gopal Prasad) 72 (2022), 51-76.

Automorphism groups of almost homogeneous varieties,
Facets of algebraic geometry. A collection in honor of William Fulton's 80th birthday. Volume 1.
London Mathematical. Society Lecture Note Series 472, 54-76, Cambridge University Press, 2022.

On models of algebraic group actions,
Proceedings of the Indian Academy of Sciences (Mathematical Sciences).
Special Issue in Memory of Prof. C. S. Seshadri 132 (2022), 1-17.