5,406 research outputs found
Economic Theory, Economic Reality and Economic Policy
This paper analyzes the opposition between the «liberals» and «statists» in the Russian political and economic thought. It demonstrates that the economic liberalization is an absolute prerequisite for the transition to sustainable socio-economic development. Such development must rely on investment activities of the state, which in the current circumstances is a necessary but not sufficient measure for reversing the negative trends. The negative developments can be prevented only through implementation, along with the institutional changes in the economic area that form a strata of economically independent entrepreneurs-innovators, of no less profound transformation in political institutions aimed at democratization of public life
Correlation Functions of Sp(2n) Invariant Higher-Spin Systems
We study the general structure of correlation functions in an
Sp(2n)-invariant formulation of systems of an infinite number of higher-spin
fields. For n=4,8 and 16 these systems comprise the conformal higher-spin
fields in space-time dimensions D=4,6 and 10, respectively, while when n=2, one
deals with conventional D=3 conformal field theories of scalars and spinors. We
show that for n>2 the Sp(2n) symmetry and current conservation makes the
3-point correlators of two (rank-one or rank-two) conserved currents with a
scalar operator be that of free theory.This situation is analogous to the one
in conventional conformal field theories, where conservation of higher-spin
currents implies that the theories are free.Comment: 26 pages, some clarifications added, published versio
The degenerate gravitino scenario
In this work, we explore the "degenerate gravitino" scenario where the mass
difference between the gravitino and the lightest MSSM particle is much smaller
than the gravitino mass itself. In this case, the energy released in the decay
of the next to lightest sypersymmetric particle (NLSP) is reduced. Consequently
the cosmological and astrophysical constraints on the gravitino abundance, and
hence on the reheating temperature, become softer than in the usual case. On
the other hand, such small mass splittings generically imply a much longer
lifetime for the NLSP. We find that, in the constrained MSSM (CMSSM), for
neutralino LSP or NLSP, reheating temperatures compatible with thermal
leptogenesis are reached for small splittings of order 10^{-2} GeV. While for
stau NLSP, temperatures of 4x10^9 GeV can be obtained even for splittings of
order of tens of GeVs. This "degenerate gravitino" scenario offers a possible
way out to the gravitino problem for thermal leptogenesis in supersymmetric
theories.Comment: 27 pages, 10 figures and 1 table. Minor typos and references fixed.
Matches published version in JCAP
Twistor-like Formulation of Super p-Branes
Closed super (p+2)-forms in target superspace are relevant for the
construction of the usual super p-brane actions. Here we construct closed super
(p+1)-forms on a {\it worldvolume superspace}. They are built out of the
pull-backs of the Kalb-Ramond super (p+1)-form and its curvature. We propose a
twistor-like formulation of a class of super p-branes which crucially depends
on the existence of these closed super (p+1)-forms.Comment: 20 pages, plain tex, CTP TAMU-67/93, UG-5/9
D=11, p=5
The equations of motion of the super five-brane in D=11 dimensions are
derived using the formalism of superembeddings. The equations describe highly
nonlinear self-interactions of a tensor multiplet in the six dimensional
worlsurface, and they have manifest worldsurface local supersymmetry. The
geometry of the target space corresponds to D=11 supergravity.Comment: 7 pages, late
- …