13,621 research outputs found
Foxconn suffers unrest at iPhone factory
This document is part of a digital collection provided by the Martin P. Catherwood Library, ILR School, Cornell University, pertaining to the effects of globalization on the workplace worldwide. Special emphasis is placed on labor rights, working conditions, labor market changes, and union organizing.CLW_2012_Report_China_foxconn_suffers.pdf: 52 downloads, before Oct. 1, 2020
The potential (iz)^m generates real eigenvalues only, under symmetric rapid decay conditions
We consider the eigenvalue problems -u"(z) +/- (iz)^m u(z) = lambda u(z), m
>= 3, under every rapid decay boundary condition that is symmetric with respect
to the imaginary axis in the complex z-plane. We prove that the eigenvalues
lambda are all positive real.Comment: 23 pages and 1 figur
Interacting with the \u27Himalayan \u3ci\u3eUmmah\u3c/i\u3e\u27. The case of Xidaotang, a Chinese Muslim Community from Lintan
This short essay discusses whether Xidaotang, a Chinese Muslim community, may be considered as belonging to the ‘Himalayan ummah’. Historically and until today, especially via trade, this community has been in close contact with the Himalayan region, understood as the mountainous zone of the Tibetan Plateau. By analyzing these trading interactions and the sociability they induce, it is possible to investigate to what extent Xidaotang members, with their own cultural background, religious practices and social experiences, have contributed to diversify the Islamic landscape in the Himalayan region, to which Amdo belongs
Maximal lengths of exceptional collections of line bundles
In this paper we construct infinitely many examples of toric Fano varieties
with Picard number three, which do not admit full exceptional collections of
line bundles. In particular, this disproves King's conjecture for toric Fano
varieties.
More generally, we prove that for any constant there exist
infinitely many toric Fano varieties with Picard number three, such that
the maximal length of exceptional collection of line bundles on is strictly
less than c\rk K_0(Y). To obtain varieties without exceptional collections of
line bundles, it suffices to put
On the other hand, we prove that for any toric nef-Fano DM stack with
Picard number three, there exists a strong exceptional collection of line
bundles on of length at least \frac34 \rk K_0(Y). The constant
is thus maximal with this property.Comment: 27 pages, no figures; misprints and typos corrected, an arithmetic
mistake in the proof of Theorem 6.2 corrected, consequently Theorem 6.3
slightly modified, new Lemma 4.4 added, description of the constructed
varieties extended, references adde
A Vanishing Result for the Universal Bundle on a Toric Quiver Variety
Let Q be a finite quiver without oriented cycles. Denote by U --> M the fine
moduli space of stable thin sincere representations of Q with respect to the
canonical stability notion. We prove Ext^i(U,U) = 0 for all i >0 and compute
the endomorphism algebra of the universal bundle U. Moreover, we obtain a
necessary and sufficient condition for when this algebra is isomorphic to the
path algebra kQ of the quiver Q. If so, then the bounded derived category of
finitely generated right kQ-modules is embedded into that of coherent sheaves
on M.Comment: 13 pages with a couple of small figures LaTeX 2.0
Quivers and moduli spaces of pointed curves of genus zero
We construct moduli spaces of representations of quivers over arbitrary
schemes and show how moduli spaces of pointed curves of genus zero like the
Grothendieck-Knudsen moduli spaces and the Losev-Manin
moduli spaces can be interpreted as inverse limits of moduli
spaces of representations of certain bipartite quivers. We also investigate the
case of more general Hassett moduli spaces of weighted
pointed stable curves of genus zero.Comment: 41 page
Tilting Bundles on Rational Surfaces and Quasi-Hereditary Algebras
Let be any rational surface. We construct a tilting bundle on .
Moreover, we can choose in such way that its endomorphism algebra is
quasi-hereditary. In particular, the bounded derived category of coherent
sheaves on is equivalent to the bounded derived category of finitely
generated modules over a finite dimensional quasi-hereditary algebra . The
construction starts with a full exceptional sequence of line bundles on and
uses universal extensions. If is any smooth projective variety with a full
exceptional sequence of coherent sheaves (or vector bundles, or even complexes
of coherent sheaves) with all groups \mExt^q for vanishing, then
also admits a tilting sheaf (tilting bundle, or tilting complex,
respectively) obtained as a universal extension of this exceptional sequence.Comment: 15 page
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