25 research outputs found
Anomalous Dimensions in Non-Supersymmetric Bifundamental Chern-Simons Theories
Non-abelian Chern-Simons theories coupled to fermions are known to provide an
interesting class of non-supersymmetric conformal fixed points
\cite{Giombi:2011kc}. These theories, particularly those based on bifundamental
matter, are important because they may provide simple non-supersymmetric
examples of the AdS/CFT correspondence. For instance, it seems natural to
conjecture that Chern-Simons theory coupled to
Majorana fermions transforming in a bi-vector representation may be dual to
pure Einstein gravity with a small negative cosmological constant in the
"M-theory" limit where and is large. While it is extremely difficult
to directly study such bifundamental theories when or even at strong 't
Hooft coupling , it is possible to calculate physical
quantities to all orders in in a
theory, in the limit , in an expansion. To illustrate this, we
calculate the anomalous dimension of the primary operator ,
to first order in , to all orders in , but with
. We also comment on possible bosonization dualities
for bifundamental Chern-Simons theories.Comment: 16 pages; v5: added correction
On the Higher-Spin Spectrum in Large N Chern-Simons Vector Models
Chern-Simons gauge theories coupled to massless fundamental scalars or
fermions define interesting non-supersymmetric 3d CFTs that possess approximate
higher-spin symmetries at large N. In this paper, we compute the scaling
dimensions of the higher-spin operators in these models, to leading order in
the 1/N expansion and exactly in the 't Hooft coupling. We obtain these results
in two independent ways: by using conformal symmetry and the classical
equations of motion to fix the structure of the current non-conservation, and
by a direct Feynman diagram calculation. The full dependence on the 't Hooft
coupling can be restored by using results that follow from the weakly broken
higher-spin symmetry. This analysis also allows us to obtain some explicit
results for the non-conserved, parity-breaking structures that appear in planar
three-point functions of the higher-spin operators. At large spin, we find that
the anomalous dimensions grow logarithmically with the spin, in agreement with
general expectations. This logarithmic behavior disappears in the strong
coupling limit, where the anomalous dimensions turn into those of the critical
O(N) or Gross-Neveu models, in agreement with the conjectured 3d bosonization
duality.Comment: 52 pages, 7 figures. v3: Minor correction
An uncommon variant of rare type of muscular dystrophy
The muscular dystrophies are a group of hereditary degenerative diseases characterised by progressive myopathy. Emery-Dreifuss muscular dystrophy (EDMD) is a rare genetically heterogenous type of muscular dystrophy characterized by early contractures (especially in the neck, elbows and ankles), slowly progressing muscle weakness more prominent in humeroperoneal region, onset in early childhood and cardiac problems. Emery-Dreifuss muscular dystrophy is commonly inherited in an X linked recessive pattern and rarely autosomal dominant inheritance or autosomal recessive fashion. Here we report a case of autosomal recessive type of Emery-Dreifuss muscular dystrophy from our hospital
Spin-orbit torques for current parallel and perpendicular to a domain wall
We report field- and current-induced domain wall (DW) depinning experiments
in Ta/Co20Fe60B20/MgO nanowires through a Hall cross geometry. While purely
field-induced depinning shows no angular dependence on in-plane fields, the
effect of the current depends crucially on the internal DW structure, which we
manipulate by an external magnetic in-plane field. We show for the first time
depinning measurements for a current sent parallel to the DW and compare its
depinning efficiency with the conventional case of current flowing
perpendicularly to the DW. We find that the maximum efficiency is similar for
both current directions within the error bars, which is in line with a
dominating damping-like spin-orbit torque (SOT) and indicates that no large
additional torques arise for currents parallel to the DW. Finally, we find a
varying dependence of the maximum depinning efficiency angle for different DWs
and pinning levels. This emphasizes the importance of our full angular scans
compared to previously used measurements for just two field directions
(parallel and perpendicular to the DW) and shows the sensitivity of the
spin-orbit torque to the precise DW structure and pinning sites.Comment: 11 pages, 3 figure
Perspectives of healthcare providers, service users, and family members about mental illness stigma in primary care settings: A multi-site qualitative study of seven countries in Africa, Asia, and Europe
Background: Stigma among healthcare providers is a barrier to the effective delivery of mental health services in primary care. Few studies have been conducted in primary care settings comparing the attitudes of healthcare providers and experiences of people with mental illness who are service users in those facilities. Such research is necessary across diverse global settings to characterize stigma and inform effective stigma reduction.
Methods: Qualitative research was conducted on mental illness stigma in primary care settings in one low-income country (Nepal), two lower-middle income countries (India, Tunisia), one upper-middle-income country (Lebanon), and three high-income countries (Czech Republic, Hungary, Italy). Qualitative interviews were conducted with 248 participants: 64 primary care providers, 11 primary care facility managers, 111 people with mental illness, and 60 family members of people with mental illness. Data were analyzed using framework analysis.
Results: Primary care providers endorsed some willingness to help persons with mental illness but reported not having appropriate training and supervision to deliver mental healthcare. They expressed that people with mental illness are aggressive and unpredictable. Some reported that mental illness is incurable, and mental healthcare is burdensome and leads to burnout. They preferred mental healthcare to be delivered by specialists. Service users did not report high levels of discrimination from primary care providers; however, they had limited expectations of support from primary care providers. Service users reported internalized stigma and discrimination from family and community members. Providers and service users reported unreliable psychiatric medication supply and lack of facilities for confidential consultations. Limitations of the study include conducting qualitative interviews in clinical settings and reliance on clinician-researchers in some sites to conduct interviews, which potentially biases respondents to present attitudes and experiences about primary care services in a positive manner.
Conclusions: Primary care providers' willingness to interact with people with mental illness and receive more training presents an opportunity to address stigmatizing beliefs and stereotypes. This study also raises important methodological questions about the most appropriate strategies to accurately understand attitudes and experiences of people with mental illness. Recommendations are provided for future qualitative research about stigma, such as qualitative interviewing by non-clinical personnel, involving non-clinical staff for recruitment of participants, conducting interviews in non-clinical settings, and partnering with people with mental illness to facilitate qualitative data collection and analysis
Erratum to: Anomalous dimensions in non-supersymmetric bifundamental Chern-Simons theories
Equation (2.16) should be replaced b