345 citations · 397 across the 12 of their papers we have counts for
12 papers
Toward the classification of threefold extremal contractions with one-dimensional fibers
Shigefumi Mori, Yuri Prokhorov
An extremal curve germ is a germ of a threefold with terminal singularities along a connected reduced complete curve~ such that there exists a -negative contraction $f…
General elephants for threefold extremal contractions with one-dimensional fibers: exceptional case
Shigefumi Mori, Yuri Prokhorov
Let be a germ of a threefold with terminal singularities along a connected reduced complete curve with a contraction such that $C = f^{-1}…
Threefold extremal curve germs with one non-Gorenstein point
Shigefumi Mori, Yuri Prokhorov
An extremal curve germ is the analytic germ of a threefold with terminal singularities along a reduced complete curve admitting a contraction whose fibers have dimension at most on…
Threefold extremal contractions of type (IIA), II
Shigefumi Mori, Yuri Prokhorov
Let be a germ of a threefold with terminal singularities along an irreducible reduced complete curve with a contraction such that $C=f^{-1}(o…
Threefold extremal contractions of type (IIA), I
Shigefumi Mori, Yuri Prokhorov
Let be a germ of a threefold with terminal singularities along an irreducible reduced complete curve with a contraction such that $C=f^{-1}(o…
Threefold extremal contractions of types (IC) and (IIB)
Shigefumi Mori, Yuri Prokhorov
Let be a germ of a threefold with terminal singularities along an irreducible reduced complete curve with a contraction such that $C=f^{-1}(o)_{…
Threefold extremal contractions of type IA
Shigefumi Mori, Yuri Prokhorov
Let be a germ of a threefold with terminal singularities along an irreducible reduced complete curve with a contraction such that $C=f^{-1}(o)_{…
On Q-conic bundles, III
Shigefumi Mori, Yuri Prokhorov
A Q-conic bundle germ is a proper morphism from a threefold with only terminal singularities to the germ of a normal surface such that fibers are connected and the anti…
Multiple fibers of del Pezzo fibrations
Shigefumi Mori, Yuri Prokhorov
We prove that a terminal three-dimensional del Pezzo fibration has no fibers of multiplicity . We also obtain a rough classification possible configurations of singular poin…
On Q-conic bundles, II
Shigefumi Mori, Yuri Prokhorov
A -conic bundle germ is a proper morphism from a threefold with only terminal singularities to the germ of a normal surface such that fibers are connected an…
On Q-conic bundles
Shigefumi Mori, Yuri Prokhorov
A -conic bundle is a proper morphism from a threefold with only terminal singularities to a normal surface such that fibers are connected and the anti-canonical divisor…
Quotients by Groupoids
Sean Keel, Shigefumi Mori
We show that if a flat group scheme acts properly, with finite stabilizers, on an algebraic space, then a quotient exists as a separated algebraic space. More generally we show any…