Articles
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12/12/2005--
12/12/2005
Multipartite states under local unitary transformations
The equivalence problem under local unitary transformation for $n$--partite
pure states is reduced to the one for $(n-1)$--partite mixed states. In
particular, a tripartite system
$\mathcal{H}_A\otimes\mathcal{H}_B\otimes\mathcal{H}_C$, where $\mathcal{H}_j$
is a finite dimensional complex Hilbert space for $j=A,B,C$, is considered and
a set of invariants under local transformations is introduced, which is
complete for the set of states whose partial trace with respect to
$\mathcal{H}_A$ belongs to the class of generic mixed states.
Sergio Albeverio
Laura Cattaneo
Shao-Ming Fei
Xiao-Hong Wang
12/01/2015--
12/01/2015
Search of MeV-GeV counterparts of TeV sources with AGILE in pointing mode
Context. Known TeV sources detected by major Cerenkov telescopes are
investigated to identify possible MeV-GeV gamma-ray counterparts. Aims. A
systematic study of the known sources in the web-based TeVCat Catalog has been
performed to search for possible gamma-ray counterpart on the AGILE data
collected during the first period of operations in observing pointing mode.
Methods. For each TeV source, a search for a possible gamma-ray counterpart
based on a multi-source Maximum Likelihood algorithm is performed on the AGILE
data taken with the GRID instrument from July 2007 to October 2009. Results. In
case of high-significance detection, the average gamma-ray flux is estimated.
For the cases of low-significance detection the 95 % Confidence Level (C.L.)
flux upper limit is given. 52 TeV sources out of 152 (corresponding to ~34 % of
the analysed sample) show a significant excess in the AGILE data covering the
pointing observation period. Conclusions. This analysis found 26 new AGILE
sources with respect to the AGILE reference catalogs, 15 of which are Galactic,
7 are extragalactic and 4 are unidentified. Detailed tables with all available
information on the analysed sources are presented.
A. Rappoldi
F. Lucarelli
C. Pittori
F. Longo
P. W. Cattaneo
F. Verrecchia
M. Tavani
A. Bulgarelli
A. W. Chen
S. Colafrancesco
I. Donnarumma
A. Giuliani
A. Morselli
S. Sabatini
S. Vercellone
06/23/2017--
05/24/2017
Radiation Hardness tests with neutron flux on different Silicon photomultiplier devices
Radiation hardness is an important requirement for solid state readout
devices operating in high radiation environments common in particle physics
experiments. The MEGII experiment, at PSI, Switzerland, investigates the
forbidden decay $\mu^+ \to \mathrm{e}^+ \gamma$. Exploiting the most intense
muon beam of the world. A significant flux of non-thermal neutrons (kinetic
energy $E_k\geq 0.5 ~MeV$) is present in the experimental hall produced along
the beamline and in the hall itself. We present the effects of neutron fluxes
comparable to the MEGII expected doses on several Silicon PhotoMulitpliers
(SiPMs). The tested models are: AdvanSiD ASD-NUV3S-P50 (used in MEGII
experiment), AdvanSiD ASD-NUV3S-P40, AdvanSiD ASD-RGB3S-P40, Hamamatsu and
Excelitas C30742-33-050-X. The neutron source is the thermal Sub-critical
Multiplication complex (SM1) moderated with water, located at the University of
Pavia (Italy). We report the change of SiPMs most important electric
parameters: dark current, dark pulse frequency, gain, direct bias resistance,
as a function of the integrated neutron fluency.
P. W. Cattaneo
T. Cervi
A. Menegolli
M. Oddone
M. Prata
M. C. Prata
M. Rossella
06/21/2017--
06/21/2017
The new semianalytic code GalICS 2.0 - Reproducing the galaxy stellar mass function and the Tully-Fisher relation simultaneously
GalICS 2.0 is a new semianalytic code to model the formation and evolution of
galaxies in a cosmological context. N-body simulations based on a Planck
cosmology are used to construct halo merger trees, track subhaloes, compute
spins and measure concentrations. The accretion of gas onto galaxies and the
morphological evolution of galaxies are modelled with prescriptions derived
from hydrodynamic simulations. Star formation and stellar feedback are
described with phenomenological models (as in other semianalytic codes). GalICS
2.0 computes rotation speeds from the gravitational potential of the dark
matter, the disc and the central bulge. As the rotation speed depends not only
on the virial velocity but also on the ratio of baryons to dark matter within a
galaxy, our calculation predicts a different Tully-Fisher relation from models
in which the rotation speed is proportional to the virial velocity. This is why
GalICS 2.0 is able to reproduce the galaxy stellar mass function and the
Tully-Fisher relation simultaneously. Our results are also in agreement with
halo masses from weak lensing and satellite kinematics, gas fractions, the
relation between star formation rate (SFR) and stellar mass, the evolution of
the cosmic SFR density, bulge-to-disc ratios, disc sizes and the Faber-Jackson
relation.
A. Cattaneo
J. Blaizot
J. E. G. Devriendt
G. A. Mamon
E. Tollet
A. Dekel
B. Guiderdoni
M. Kucukbas
A. C. R. Thob
02/20/1994--
02/04/1994
Moduli Spaces of Curves with Homology Chains and c=1 Matrix Models
We show that introducing a periodic time coordinate in the models of
Penner-Kontsevich type generalizes the corresponding constructions to the case
of the moduli space ${\cal S}_{gn}^k$ of curves $C$ with homology chains
$\gamma\in H_1(C,\zet_k)$. We make a minimal extension of the resulting models
by adding a kinetic term, and we get a new matrix model which realizes a simple
dynamics of $\zet_k$-chains on surfaces. This gives a representation of $c=1$
matter coupled to two-dimensional quantum gravity with the target space being a
circle of finite radius, as studied by Gross and Klebanov.
A. S. Cattaneo
A. Gamba
M. Martellini
11/08/2020--
11/08/2020
Bott-Cattaneo-Rossi invariants for long knots in asymptotic homology $\mathbb R^3$
In this article, we express the Alexander polynomial of null-homologous long
knots in punctured rational homology $3$-spheres in terms of integrals over
configuration spaces. To get such an expression, we use a previously
established formula, which gives generalized Bott-Cattaneo-Rossi invariants in
terms of the Alexander polynomial and vice versa, and we relate these
Bott-Cattaneo-Rossi invariants to the perturbative expansion of Chern-Simons
theory.
David Leturcq
06/09/2022--
06/09/2022
The tempered space-fractional Cattaneo equation
We consider the time-fractional Cattaneo equation involving the tempered
Caputo space-fractional derivative. We find the characteristic function of the
related process and we explain the main differences with previous stochastic
treatments of the time-fractional Cattaneo equation.
Luisa Beghin
Roberto Garra
Francesco Mainardi
Gianni Pagnini
01/15/2018--
01/15/2018
The design of the MEG II experiment
The MEG experiment, designed to search for the mu+->e+ gamma decay at a
10^-13 sensitivity level, completed data taking in 2013. In order to increase
the sensitivity reach of the experiment by an order of magnitude to the level
of 6 x 10-14 for the branching ratio, a total upgrade, involving substantial
changes to the experiment, has been undertaken, known as MEG II. We present
both the motivation for the upgrade and a detailed overview of the design of
the experiment and of the expected detector performance.
A. M. Baldini
E. Baracchini
C. Bemporad
F. Berg
M. Biasotti
G. Boca
P. W. Cattaneo
G. Cavoto
F. Cei
M. Chiappini
G. Chiarello
C. Chiri
G. Cocciolo
A. Corvaglia
A. de Bari
M. De Gerone
A. D'Onofrio
M. Francesconi
Y. Fujii
L. Galli
F. Gatti
F. Grancagnolo
M. Grassi
D. N. Grigoriev
M. Hildebrandt
Z. Hodge
F. Grancagnolo
M. Grassi
D. N. Grigoriev
M. Hildebrandt
Z. Hodge
K. Ieki
F. Ignatov
R. Iwai
T. Iwamoto
D. Kaneko
K. Kasami
P. -R. Kettle
B. I. Khazin
N. Khomutov
A. Korenchenko
N. Kravchuk
T. Libeiro
M. Maki
N. Matsuzawa
S. Mihara
M. Milgie
W. Molzon
Toshinori Mori
F. Morsani
A. Mtchedilishvili
M. Nakao
S. Nakaura
D. Nicoló
H. Nishiguchi
M. Nishimura
S. Ogawa
W. Ootani
M. Panareo
A. Papa
A. Pepino
G. Piredda
A. Popov
F. Raffaelli
F. Renga
E. Ripiccini
S. Ritt
M. Rossella
G. Rutar
R. Sawada
G. Signorelli
M. Simonetta
G. F. Tassielli
Y. Uchiyama
M. Usami
M. Venturini
C. Voena
K. Yoshida
Yu. V. Yudin
Y. Zhang
03/24/2006--
01/29/2005
Relative formality theorem and quantisation of coisotropic submanifolds
We prove a relative version of Kontsevich's formality theorem. This theorem
involves a manifold M and a submanifold C and reduces to Kontsevich's theorem
if C=M. It states that the DGLA of multivector fields on an infinitesimal
neighbourhood of C is L-infinity-quasiisomorphic to the DGLA of
multidifferential operators acting on sections of the exterior algebra of the
conormal bundle. Applications to the deformation quantisation of coisotropic
submanifolds are given. The proof uses a duality transformation to reduce the
theorem to a version of Kontsevich's theorem for supermanifolds, which we also
discuss. In physical language, the result states that there is a duality
between the Poisson sigma model on a manifold with a D-brane and the Poisson
sigma model on a supermanifold without branes (or, more properly, with a brane
which extends over the whole supermanifold).
Alberto S. Cattaneo
Giovanni Felder
09/26/2005--
09/26/2005
The spectrum of the averaging operator on a network (metric graph)
A network is a countable, connected graph X viewed as a one-complex, where
each edge [x,y]=[y,x] (x,y in X^0, the vertex set) is a copy of the unit
interval within the graph's one-skeleton X^1 and is assigned a positive
conductance c(xy). A reference "Lebesgue" measure on X^1 is built up by using
Lebesgue measure with total mass c(xy) on each edge [x,y]. There are three
natural operators on X : the transition operator P acting on functions on X^0
(the reversible Markov chain associated with the conductances), the averaging
operator A over spheres of radius 1 on X^1, and the Laplace operator on X^1
(with Kirchhoff conditions weighted by c(.) at the vertices). The relation
between the l^2-spectrum of P and the H^2-spectrum of the Laplacian was
described by Cattaneo (Mh. Math. 124, 1997). In this paper we describe the
relation between the l^2-spectrum of P and the L^2-spectrum of A.
Donald I. Cartwright
Wolfgang Woess
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