4,466 research outputs found
Population ageing and public pension reforms in a small open economy
This paper aims to address the issue of public pension reforms under demographic ageing that is likely to occur in Europe over the next 50 years. Three possible scenarios are analysed in a Blanchard OLG framework. These include: i) a decrease both in public pensions and the lump sum
labour income tax, ii) a decrease both in public pensions and the distortionary corporate tax, iii) an increase in the retirement age. The analysis focuses on the effects of these fiscal policies on key economic variables such as consumption, private and public debt, output and wages. Quantitative experiments assess the impact of different fiscal policies in terms of public debt sustainability but most importantly suggest policies that smooth the
transition of the economy to the new equilibrium. The main results suggest that the adverse effects of pension reforms on consumption are moderated when they are accompanied by appropriate taxation policies. In particular, when the tax response is rapid most of the adverse movement in consumption is avoided while public and national debt reach lower equilibrium levels
On the non-abelian Brumer-Stark conjecture and the equivariant Iwasawa main conjecture
We show that for an odd prime p, the p-primary parts of refinements of the
(imprimitive) non-abelian Brumer and Brumer-Stark conjectures are implied by
the equivariant Iwasawa main conjecture (EIMC) for totally real fields.
Crucially, this result does not depend on the vanishing of the relevant Iwasawa
mu-invariant. In combination with the authors' previous work on the EIMC, this
leads to unconditional proofs of the non-abelian Brumer and Brumer-Stark
conjectures in many new cases.Comment: 33 pages; to appear in Mathematische Zeitschrift; v3 many minor
updates including new title; v2 some cohomological arguments simplified; v1
is a revised version of the second half of arXiv:1408.4934v
On equivariant characteristic ideals of real classes
Let be an odd prime, an abelian totally real number field,
its cyclotomic -extension,
We give an explicit description of the equivariant characteristic ideal of
over for all odd by applying M. Witte's formulation of an equivariant main conjecture (or
"limit theorem") due to Burns and Greither. This could shed some light on
Greenberg's conjecture on the vanishing of the -invariant of
$F_\infty/F.
Magnetic aspects of QCD at finite density and temperature
Some magnetic aspects of QCD are discussed at finite density and temperature.
Possibility of spontaneous magnetization is studied within Landau Fermi-liquid
theory, and the important roles of the screening effects for gluon propagation
are elucidated. Static screening for the longitudinal gluons improves the
infrared singularities, while the transverse gluons receive only dynamic
screening. The latter property gives rise to a novel non-Fermi-liquid behaviour
for the magnetic susceptibility. Appearance of a density-wave state is also
discussed in relation to chiral transition, where pseudoscalar condensate as
well as scalar one takes a spatially non-uniform form in a chirally invariant
way. Accordingly magnetization of quark matter oscillates like spin density
wave. A hadron-quark continuity is suggested in this aspect, remembering pion
condensation in hadronic phase.Comment: 6 pages, 8 figures, Proc. of INPN2010 to appear in J. Phy
Interpolation Parameter and Expansion for the Three Dimensional Non-Trivial Scalar Infrared Fixed Point
We compute the non--trivial infrared --fixed point by means of an
interpolation expansion in fixed dimension. The expansion is formulated for an
infinitesimal momentum space renormalization group. We choose a coordinate
representation for the fixed point interaction in derivative expansion, and
compute its coordinates to high orders by means of computer algebra. We compute
the series for the critical exponent up to order twenty five of
interpolation expansion in this representation, and evaluate it using \pade,
Borel--\pade, Borel--conformal--\pade, and Dlog--\pade resummation. The
resummation returns as the value of .Comment: 29 pages, Latex2e, 2 Postscript figure
Pequenas frutas, grandes perspectivas.
Made available in DSpace on 2012-07-03T01:00:40Z (GMT). No. of bitstreams: 1
NICKELCultivarHFv5n25p212004.pdf: 501701 bytes, checksum: b38a432efe4e79d816a432f5fa2685db (MD5)
Previous issue date: 2005-02-1
Experimental mathematics on the magnetic susceptibility of the square lattice Ising model
We calculate very long low- and high-temperature series for the
susceptibility of the square lattice Ising model as well as very long
series for the five-particle contribution and six-particle
contribution . These calculations have been made possible by the
use of highly optimized polynomial time modular algorithms and a total of more
than 150000 CPU hours on computer clusters. For 10000 terms of the
series are calculated {\it modulo} a single prime, and have been used to find
the linear ODE satisfied by {\it modulo} a prime.
A diff-Pad\'e analysis of 2000 terms series for and
confirms to a very high degree of confidence previous conjectures about the
location and strength of the singularities of the -particle components of
the susceptibility, up to a small set of ``additional'' singularities. We find
the presence of singularities at for the linear ODE of ,
and for the ODE of , which are {\it not} singularities
of the ``physical'' and that is to say the
series-solutions of the ODE's which are analytic at .
Furthermore, analysis of the long series for (and )
combined with the corresponding long series for the full susceptibility
yields previously conjectured singularities in some , .
We also present a mechanism of resummation of the logarithmic singularities
of the leading to the known power-law critical behaviour occurring
in the full , and perform a power spectrum analysis giving strong
arguments in favor of the existence of a natural boundary for the full
susceptibility .Comment: 54 pages, 2 figure
Molecular variants of Grapevine rupestris stem pitting-associated virus infecting grapevines (Vitis spp.) in Brazil.
Grapevine rupestris stem pitting-associated virus (GRSPaV) is one of the most common viruses of grapevine. It is involved in the graft-transmissible disease rupestris stem pitting of the rugose wood complex. The objective of the research was to perform the molecular characterization of the coat protein (CP) gene of sixteen Brazilian GRSPaV isolates aiming to determine the occurrence of molecular variants (strains) of this virus. Nine grapevine samples were evaluated, from which dsRNA was extracted. Nucleotide sequences were generated by Next generation sequencing (NGS). Fifteen complete sequences of the GRSPaV CP gene were obtained and phylogenetically analyzed. Multiple alignments of the sequences showed identities of nucleotides ranging from 82% to 99%, suggesting high variability among the CPs of Brazilian isolates. The study revealed that genetic variability of GRSPaV comprising three molecular variants is also present in Brazilian grapevine genotypes.Key words: GRSPaV, Foveavirus, strains, lineages, genetic variability. O GRSPaV Ă© um dos vĂrus mais comuns da videira. EstĂĄ associado Ă doença transmissĂvel por enxertia denominada caneluras de rupestris que compĂ”e o complexo do lenho rugoso. O objetivo do trabalho foi realizar a caracterização molecular do gene da proteĂna capsidial (CP) de 16 isolados brasileiros de GRSPaV visando determinar a ocorrĂȘncia de variantes moleculares desse vĂrus. Nove amostras de videira foram avaliadas das quais foi extraĂdo dsRNA. As sequĂȘncias de nucleotĂdeos foram geradas pelo sequenciamento de nova geração (NGS). Quinze sequĂȘncias completas do gene CP de GRSPaV foram obtidas e filogeneticamente analisadas. Os alinhamentos mĂșltiplos entre as sequĂȘncias mostraram identidades de nucleotĂdeos variando de 82% a 99%, sugerindo alta variabilidade entre as CPs de isolados brasileiros. O estudo revelou que a variabilidade genĂ©tica de GRSPaV compreendendo trĂȘs variantes moleculares tambĂ©m estĂĄ presente nos genĂłtipos de videira no Brasil. Palavras-chave: GRSPaV, Foveavirus, estirpes, linhagens, variabilidade genĂ©tica
The diagonal Ising susceptibility
We use the recently derived form factor expansions of the diagonal two-point
correlation function of the square Ising model to study the susceptibility for
a magnetic field applied only to one diagonal of the lattice, for the isotropic
Ising model.
We exactly evaluate the one and two particle contributions
and of the corresponding susceptibility, and obtain linear
differential equations for the three and four particle contributions, as well
as the five particle contribution , but only modulo a given
prime. We use these exact linear differential equations to show that, not only
the russian-doll structure, but also the direct sum structure on the linear
differential operators for the -particle contributions are
quite directly inherited from the direct sum structure on the form factors .
We show that the particle contributions have their
singularities at roots of unity. These singularities become dense on the unit
circle as .Comment: 18 page
Feasibility study for a Scanning Celestial Attitude Determination System /SCADS/ for three axis attitude determination at a Command and Data Acquisition /CDA/ station Final report
Scanning Celestial Attitude Determination System /SCADS/ for three axis attitude determination at Command and Data Acquisition /CDA/ statio
- âŠ