44 research outputs found
Stability issues with baryons in AdS/CFT
We consider baryon vertices within the gauge/gravity correspondence for a
class of curved backgrounds. The holographic description based on the N=4 SYM
theory for SU(N) allows classical solutions representing bound states of
k-quarks with k less than or equal to N. We construct the corresponding
classical configurations and perform a stability analysis. We present the
details for the theory at the conformal point and at finite temperature and
show that there is a critical value of k, below which there is instability.
This may also arise when the baryon reaches a critical size. We also extend our
treatment to magnetically charged baryon vertices.Comment: v1: 22 Pages, 4 figures; v2: A reference corrected and a reference
adde
Renormalization of Lorentz non-invariant actions and manifest T-duality
We study general two-dimensional sigma-models which do not possess manifest
Lorentz invariance. We show how demanding that Lorentz invariance is recovered
as an emergent on-shell symmetry constrains these sigma-models. The resulting
actions have an underlying group-theoretic structure and resemble Poisson-Lie
T-duality invariant actions. We consider the one-loop renormalization of these
models and show that the quantum Lorentz anomaly is absent. We calculate the
running of the couplings in general and show, with certain non-trivial
examples, that this agrees with that of the T-dual models obtained classically
from the duality invariant action. Hence, in these cases solving constraints
before and after quantization are commuting operations.Comment: V2: reference added, version to appear in Nucl. Phys.
Canonical pure spinor (Fermionic) T-duality
We establish that the recently discovered fermionic T-duality can be viewed
as a canonical transformation in phase space. This requires a careful treatment
of constrained Hamiltonian systems. Additionally, we show how the canonical
transformation approach for bosonic T-duality can be extended to include
Ramond--Ramond backgrounds in the pure spinor formalism.Comment: 14 page
Linking internal marketing with customer outcomes
Purpose â The purpose of this study is to explore how the adoption of an internal marketing (IM) programme in a retail banking setting enhances some positive employee behaviours that promote customer perceived service quality. Design/methodology/approach â A multilevel research design is adopted which draws evidence from branch managers, employees and customers in order to investigate whether branch managerâs adoption of an IM philosophy affects front-line employee responsiveness to the firmâs IM strategies and their levels of motivation, empowerment and organizational identification (OI), respectively. Findings â Results indicate that managerâs IM adoption can enhance employee adoption of IM and raises their levels of motivation, empowerment and OI. The moderating role of manager-employee dissimilarity is also discussed. Finally, findings confirm that employee motivation, empowerment and OI affect customer perceptions of service quality. Originality/value â This study provides an important shift by formally including IM into multilevel marketing research and establishes another link in the IM-organizational performance relationship, uncovering some behavioural routes through which the positive effects of IM can add to the achievement of firmâs external marketing objectives
Self-dual gravitational instantons and geometric flows of all Bianchi types
We investigate four-dimensional, self-dual gravitational instantons endowed
with a product structure RxM_3, where M_3 is homogeneous of Bianchi type. We
analyze the general conditions under which Euclidean-time evolution in the
gravitational instanton can be identified with a geometric flow of a metric on
M_3. This includes both unimodular and non-unimodular groups, and the
corresponding geometric flow is a general Ricci plus Yang-Mills flow
accompanied by a diffeomorphism.Comment: Latex, 12 pages; Final versio
Non-singlet Baryons in Less Supersymmetric Backgrounds
We analyze the holographic description of non-singlet baryons in various
backgrounds with reduced supersymmetries and/or confinement. We show that they
exist in all AdS_5xY_5 backgrounds with Y_5 an Einstein manifold bearing five
form flux, for a number of quarks 5N/8< k< N, independently on the
supersymmetries preserved. This result still holds for gamma_i deformations. In
the confining Maldacena-Nunez background non-singlet baryons also exist,
although in this case the interval for the number of quarks is reduced as
compared to the conformal case. We generalize these configurations to include a
non-vanishing magnetic flux such that a complementary microscopical description
can be given in terms of lower dimensional branes expanding into fuzzy baryons.
This description is a first step towards exploring the finite 't Hooft coupling
region.Comment: 36 Pages, 1 figure, Latex, v2: few minor changes, JHEP versio
ABJM Baryon Stability and Myers effect
We consider magnetically charged baryon vertex like configurations in AdS^4 X
CP^3 with a reduced number of quarks l. We show that these configurations are
solutions to the classical equations of motion and are stable beyond a critical
value of l. Given that the magnetic flux dissolves D0-brane charge it is
possible to give a microscopical description in terms of D0-branes expanding
into fuzzy CP^n spaces by Myers dielectric effect. Using this description we
are able to explore the region of finite 't Hooft coupling.Comment: 29 pages, Latex; minor changes; version to appear in JHE
Critical solutions in topologically gauged N=8 CFTs in three dimensions
In this paper we discuss some special (critical) background solutions that
arise in topological gauged three-dimensional CFTs with SO(N)
gauge group. These solutions solve the TMG equations (containing the parameters
and ) for a certain set of values of obtained by varying the
number of scalar fields with a VEV. Apart from Minkowski, chiral round
and null-warped (or Schr\"odinger(z=2)) we identify also a more exotic
solution recently found in by Ertl, Grumiller and Johansson. We also
discuss the spectrum, symmetry breaking pattern and the supermultiplet
structure in the various backgrounds and argue that some properties are due to
their common origin in a conformal phase. Some of the scalar fields, including
all higgsed ones, turn out to satisfy three-dimensional singleton field
equations. Finally, we note that topologically gauged ABJ(M)
theories have a similar, but more restricted, set of background solutions.Comment: 34 pages, v2: minor corrections, note about a new solution added in
final section, v3: two footnotes adde
Integrable deformations of the Gk1ĂGk2/Gk1+k2 coset CFTs
We study the effective action for the integrable λ-deformation of the Gk1ĂGk2/Gk1+k2 coset CFTs. For unequal levels theses models do not fall into the general discussion of λ-deformations of CFTs corresponding to symmetric spaces and have many attractive features. We show that the perturbation is driven by parafermion bilinears and we revisit the derivation of their algebra. We uncover a non-trivial symmetry of these models parametric space, which has not encountered before in the literature. Using field theoretical methods and the effective action we compute the exact in the deformation parameter ÎČ-function and explicitly demonstrate the existence of a fixed point in the IR corresponding to the Gk1âk2ĂGk2/Gk1 coset CFTs. The same result is verified using gravitational methods for G=SU(2). We examine various limiting cases previously considered in the literature and found agreement. © 201