16,937 research outputs found
Diagnosing the UK Productivity Slowdown: Which Sectors Matter and Why?
This paper explores the slowdown in labour productivity growth in the UK and other advanced economies by decomposing its growth into contributions from different sectors of the economy, looking at both within-industry productivity growth and labour reallocation between sectors. We find that the within-industry contribution is the main source of the slowdown. Comparing trends pre- and post-2008, the aggregate productivity slowdown can be attributed largely to the manufacturing sector and the information and communication (ICT) sector. Disaggregating further, the UK productivity growth slowdown can be attributed mainly to transport equipment and pharmaceuticals within manufacturing, and computer software and telecommunications within ICT. Strikingly, these are advanced, high value-added sectors considered to be strengths of the UK economy. Looking across other advanced economies, our results confirm that manufacturing and ICT sectors are the main drivers of the slowdown, to differing degrees. Part of the explanation for the slowdown in in these sectors may relate to the underlying question of how to construct deflators for a modern economy when technological and structural changes are leading to large relative price shifts. The structure and supply chains of the key slowdown sectors also merit further investigation
Configuration mixing of angular-momentum projected triaxial relativistic mean-field wave functions. II. Microscopic analysis of low-lying states in magnesium isotopes
The recently developed structure model that uses the generator coordinate
method to perform configuration mixing of angular-momentum projected wave
functions, generated by constrained self-consistent relativistic mean-field
calculations for triaxial shapes (3DAMP+GCM), is applied in a systematic study
of ground states and low-energy collective states in the even-even magnesium
isotopes Mg. Results obtained using a relativistic point-coupling
nucleon-nucleon effective interaction in the particle-hole channel, and a
density-independent -interaction in the pairing channel, are compared
to data and with previous axial 1DAMP+GCM calculations, both with a
relativistic density functional and the non-relativistic Gogny force. The
effects of the inclusion of triaxial degrees of freedom on the low-energy
spectra and E2 transitions of magnesium isotopes are examined.Comment: 28 pages, 11 figures and 1 tabl
On Size and Shape of the Average Meson Fields in the Semibosonized Nambu & Jona-Lasinio Model
We consider a two-flavor Nambu \& Jona-Lasinio model in Hartree approximation
involving scalar-isoscalar and pseudoscalar-isovector quark-quark interactions.
Average meson fields are defined by minimizing the effective Euklidean action.
The fermionic part of the action, which contains the full Dirac sea, is
regularized within Schwinger's proper-time scheme. The meson fields are
restricted to the chiral circle and to hedgehog configurations. The only
parameter of the model is the constituent quark mass which simultaneously
controls the regularization. We evaluate meson and quark fields
self-consistently in dependence on the constituent quark mass. It is shown that
the self-consistent fields do practically not depend on the constituent quark
mass. This allows us to define a properly parameterized reference field which
for physically relevant constituent masses can be used as a good approximation
to the exactly calculated one. The reference field is chosen to have correct
behaviour for small and large radii. To test the agreement between
self-consistent and reference fields we calculate several observables like
nucleon energy, mean square radius, axial-vector constant and delta-nucleon
mass splitting in dependence on the constituent quark mass. The agreement is
found to be very well. Figures available on request.Comment: 12 pages (LATEX), 3 figures available on request, report FZR 93-1
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