67,719 research outputs found
Physics at COSY
The COSY accelerator in J\'ulich is presented together with its internal and
external detectors. The physics programme performed recently is discussed with
emphasis on strangeness physics.Comment: Invited talk given at the "10th International Symposium on
Meson-Nucleon Physics and the Structure of the Nucleon (MENU04)," IHEP,
Beijing, China, 30/Aug.-4/Sept./0
D-Instanton Corrections as (p,q)-String Effects and Non-Renormalization Theorems
We discuss higher derivative interactions in the type IIB superstring in ten
dimensions. From the fundamental string point of view, the non-perturbative
corrections are due to D-instantons. We argue that they can alternatively be
understood as arising from -strings. We derive a non-renormalization
theorem for eight-derivative bosonic interactions, which states that terms
involving either NS-NS or R-R fields occur at tree-level and one-loop only. By
using the symmetry of M-theory on , we show that in order for
the possible interactions in M-theory to have a
consistent perturbative expansion in nine dimensions, must be odd. Thus,
only terms can be present in M-theory and their string
theory counterparts arise at and loops. Finally, we treat an example
of fermionic term.Comment: 24 pages, latex, additional arguments for the perturbative form of
the eight-derivative interaction
General features of Bianchi-I cosmological models in Lovelock gravity
We derived equations of motion corresponding to Bianchi-I cosmological models
in the Lovelock gravity. Equations derived in the general case, without any
specific ansatz for any number of spatial dimensions and any order of the
Lovelock correction. We also analyzed the equations of motion solely taking
into account the highest-order correction and described the drastic difference
between the cases with odd and even numbers of spatial dimensions. For
power-law ansatz we derived conditions for Kasner and generalized Milne regimes
for the model considered. Finally, we discuss the possible influence of matter
in the form of perfect fluid on the solutions obtained.Comment: extended version of published Brief Repor
Graduate Student Impairment: The Impact on Counselor Training Programs
This article focuses on the issue of student impairment in graduate level counselor training programs and the factors that affect it, including: A definition of graduate student impairment; the prevalence of student impairment in counselor training programs; an explanation of the legal consequences when addressing student impairment; organizational issues in universities dealing with this issue; and, the impact of graduate student impairment on the counseling professions
Relativistic Harmonic Oscillator Revisited
The familiar Fock space commonly used to describe the relativistic harmonic
oscillator, for example as part of string theory, is insufficient to describe
all the states of the relativistic oscillator. We find that there are three
different vacua leading to three disconnected Fock sectors, all constructed
with the same creation-annihilation operators. These have different spacetime
geometric properties as well as different algebraic symmetry properties or
different quantum numbers. Two of these Fock spaces include negative norm
ghosts (as in string theory) while the third one is completely free of ghosts.
We discuss a gauge symmetry in a worldline theory approach that supplies
appropriate constraints to remove all the ghosts from all Fock sectors of the
single oscillator. The resulting ghost free quantum spectrum in d+1 dimensions
is then classified in unitary representations of the Lorentz group SO(d,1).
Moreover all states of the single oscillator put together make up a single
infinite dimensional unitary representation of a hidden global symmetry
SU(d,1), whose Casimir eigenvalues are computed. Possible applications of these
new results in string theory and other areas of physics and mathematics are
briefly mentioned.Comment: 41 pages, 2 figures, LaTe
The low energy expansion of the one-loop type II superstring amplitude
The one-loop four-graviton amplitude in either of the type II superstring
theories is expanded in powers of the external momenta up to and including
terms of order s^4 log s R^4, where R^4 denotes a specific contraction of four
linearized Weyl tensors and s is a Mandelstam invariant. Terms in this series
are obtained by integrating powers of the two-dimensional scalar field theory
propagator over the toroidal world-sheet as well as the moduli of the torus.
The values of these coefficients match expectations based on duality relations
between string theory and eleven-dimensional supergravity.Comment: harvmac (b), 25 pages, 3 eps figures. v2: Factors of 2 corrected.
Conclusion unchange
Servitisation and value co-production in the UK music industry
Since the rise of music on the internet, record companies have reported falling sales of physical products. This has occurred at a time when technology has radically increased choice, availability and the opportunity for the consumer to purchase music. As the music industry has moved from a product to a service business model, has the loss of sales meant they have not taken their customers with them? This paper provides a description of different music consumers based upon quantitative analysis of consumer characteristics. The paper then undertakes an exploration of the relationship between the consumer groups and their purchasing preference in relation to intangible ‘service’ purchase such as downloaded music and the purchase of a tangible physical product such as CDs or vinyl. In addition, we analyse the relationship between consumer types and their propensity to actively engage with music
communities, such as through engagement with social media, and thus their willingness to coproduce greater value. Finally we explore the moderating effects of age and time devoted to listening to music on purchasing preferences and music discovery
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