11,869 research outputs found
T-motives
Considering a (co)homology theory on a base category
as a fragment of a first-order logical theory we here construct
an abelian category which is universal with respect
to models of in abelian categories. Under mild conditions on the
base category , e.g. for the category of algebraic schemes, we get
a functor from to
the category of chain complexes of ind-objects of .
This functor lifts Nori's motivic functor for algebraic schemes defined over a
subfield of the complex numbers. Furthermore, we construct a triangulated
functor from to Voevodsky's motivic
complexes.Comment: Added reference to arXiv:1604.00153 [math.AG
Effects of Rescattering in (e,e'p) Reactions within a Semiclassical Model
The contribution of rescattering to final state interactions in (e,e'p) cross
sections is studied for medium and high missing energies using a semiclassical
model. This approach considers two-step processes that lead to the emission of
both nucleons.
The effects of nuclear transparency are accounted for in a Glauber inspired
approach and the dispersion effects of the medium at low energies are included.
It is found that rescattering is strongly reduced in parallel kinematics.
At high missing energy and momenta, the distortion of the short-range
correlated tail of the spectral function is dominated by a rearrangement of
that strength itself. In perpendicular kinematics, a further enhancement of the
experimental yield is due to strength that is originally in the mean field
region.
This contribution becomes negligible at large missing momenta.Comment: 10 pages, 9 figures. Minor corrections: improved figures and few
comments adde
1-motivic sheaves and the Albanese functor
We introduce n-generated sheaves and n-motivic sheaves, describing completely
for n = 0, 1 and proposing a conjecture for n > 1. We then obtain functors
L\pi_0 and LAlb on DM_{eff}(k) deriving \pi_0 and Alb. The functor LAlb extends
the one constructed (by the second author jointly with B.Kahn) to
non-necessarily geometric motives. These functors are then used to define
higher N\'eron-Severi groups and higher Albanese sheaves. The latter may be
considered as an algebraic avatar of Deligne (co)homology.Comment: 54 pages, fully revised exposition with a new "structure theorem" for
1-motivic sheaves, see Theorem 1.3.10, including finitely presented (or
constructible) 1-motivic sheave
Albanese and Picard 1-motives
We define, in a purely algebraic way, 1-motives , ,
and associated with any algebraic scheme over an
algebraically closed field of characteristic zero. For over \C of
dimension the Hodge realizations are, respectively, ,
, and .Comment: 5 pages, LaTeX, submitted as CR Not
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