288 research outputs found
Super-Yang-Mills and M5-branes
We uplift 5-dimensional super-Yang-Mills theory to a 6-dimensional gauge
theory with the help of a space-like constant vector , whose norm
determines the Yang-Mills coupling constant. After the localization of
the 6D gauge theory acquires Lorentzian invariance as well as scale invariance.
We discuss KK states, instantons and the flux quantization. The 6D theory
admits extended solutions like 1/2 BPS `strings' and monopoles.Comment: 15 pages; minor changes, to appear in JHE
Relating U(N)xU(N) to SU(N)xSU(N) Chern-Simons Membrane theories
By integrating out the U(1)_B gauge field, we show that the U(n)xU(n) ABJM
theory at level k is equivalent to a Z_k identification of the
(SU(n)xSU(n))/Z_n Chern-Simons theory, but only when n and k are coprime. As a
consequence, the k=1 ABJM model for two M2-branes in R^8 can be identified with
the N=8 (SU(2)xSU(2))/Z_2 theory. We also conjecture that the U(2)xU(2) ABJM
model at k=2 is equivalent to the N=8 SU(2)xSU(2)-theory.Comment: 16 pages, Latex; v2: references added; v3: Clarifications adde
A population scale analysis of rare SNCA variation in the UK Biobank
Parkinson's disease (PD) is a complex neurodegenerative disease with a variety of genetic and environmental factors contributing to disease. The SNCA gene encodes for the alpha-synuclein protein which plays a central role in PD, where aggregates of this protein are one of the pathological hallmarks of disease. Rare point mutations and copy number gains of the SNCA gene have been shown to cause autosomal dominant PD, and common DNA variants identified using Genome-Wide Association Studies (GWAS) are a moderate risk factor for PD. The UK Biobank is a large-scale population prospective study including ~500,000 individuals that has revolutionized human genetics. Here we assessed the frequency of SNCA variation in this cohort and identified 30 subjects carrying variants of interest including duplications (nāÆ=āÆ6), deletions (nāÆ=āÆ6) and large complex likely mosaic events (nāÆ=āÆ18). No known pathogenic missense variants were identified. None of these subjects were reported to be a PD case, although it is possible that these individuals may develop PD at a later age, and whilst three had known prodromal features, these did not meet defined clinical criteria for being considered āprodromalā cases. Seven of the 18 large complex carriers showed a history of blood based cancer. Overall, we identified copy number variants in the SNCA region in a large population based cohort without reported PD phenotype and symptoms. Putative mosaicism of the SNCA gene was identified, however, it is unclear whether it is associated with PD. These individuals are potential candidates for further investigation by performing SNCA RNA and protein expression studies, as well as promising clinical trial candidates to understand how duplication carriers potentially escape PD
On thermodynamics of N=6 superconformal Chern-Simons theory
We study thermodynamics of N=6 superconformal Chern-Simons theory by
computing quantum corrections to the free energy. We find that in weakly
coupled ABJM theory on R(2) x S(1), the leading correction is non-analytic in
the 't Hooft coupling lambda, and is approximately of order lambda^2
log(lambda)^3. The free energy is expressed in terms of the scalar thermal mass
m, which is generated by screening effects. We show that this mass vanishes to
1-loop order. We then go on to 2-loop order where we find a finite and positive
mass squared m^2. We discuss differences in the calculation between Coulomb and
Lorentz gauge. Our results indicate that the free energy is a monotonic
function in lambda which interpolates smoothly to the N^(3/2) behaviour at
strong coupling.Comment: 29 pages. v2: references added. v3: minor changes, references added,
published versio
Boundary Conditions for Interacting Membranes
We investigate supersymmetric boundary conditions in both the Bagger-Lambert
and the ABJM theories of interacting membranes. We find boundary conditions
associated to the fivebrane, the ninebrane and the M-theory wave. For the ABJM
theory we are able to understand the enhancement of supersymmetry to produce
the (4,4) supersymmetry of the self-dual string. We also include supersymmetric
boundary conditions on the gauge fields that cancel the classical gauge anomaly
of the Chern-Simons terms.Comment: 36 pages, latex, v2 minor typos correcte
On the worldsheet theory of the type IIA AdS(4) x CP(3) superstring
We perform a detailed study of the type IIA superstring in AdS(4) x CP(3).
After introducing suitable bosonic light-cone and fermionic kappa worldsheet
gauges we derive the pure boson and fermion SU(2|2) x U(1) covariant light-cone
Hamiltonian up to quartic order in fields.
As a first application of our derivation we calculate energy shifts for
string configurations in a closed fermionic subsector and successfully match
these with a set of light-cone Bethe equations. We then turn to investigate the
mismatch between the degrees of freedom of scattering states and oscillatory
string modes. Since only light string modes appear as fundamental Bethe roots
in the scattering theory, the physical role of the remaining massive
oscillators is rather unclear. By continuing a line of research initiated by
Zarembo, we shed light on this question by calculating quantum corrections for
the propagators of the bosonic massive fields. We show that, once loop
corrections are incorporated, the massive coordinates dissolve in a continuum
state of two light particles.Comment: 40 pages, 2 figures. v3: Minor clarifications made and reference list
updated. Published version
Charges of Monopole Operators in Chern-Simons Yang-Mills Theory
We calculate the non-abelian R-charges of BPS monopole operators in
three-dimensional gauge theories with N=3 supersymmetry. This class of models
includes ABJM theory, the proposed gauge theory dual of M-theory on AdS_4 x
S^7/Z_k, as a special case. In the UV limit of the N=3 theories the Yang-Mills
coupling becomes weak and the monopole operators are described by classical
backgrounds. This allows us to find their SU(2)_R charges in a one-loop
computation which by virtue of the non-renormalization of non-abelian R-charges
yields the exact result for any value of the coupling. The spectrum of SU(2)_R
charges is found by quantizing the SU(2)/U(1) collective coordinate of the BPS
background, whose dynamics is that of a charged particle on a sphere with a
Wess-Zumino term representing a magnetic monopole at its center. If the
Wess-Zumino coefficient is h, then the smallest possible SU(2)_R representation
for BPS monopole operators has spin |h|/2. We find, in agreement with earlier
proposals, that h is proportional to the sum of the U(1)_R charges of all the
fermion fields weighted by the effective monopole charges determined by their
gauge representations. The field content of ABJM theory is such that h=0. This
proves for any Chern-Simons level k the existence of monopole operators which
are singlets under all global symmetries and have vanishing scaling dimensions.
These operators are essential for matching the spectrum of the ABJM theory with
supergravity and for the supersymmetry enhancement to N=8.Comment: 31 pages, 3 figures, v2: reference added, discussion of collective
coordinate wave-function adde
Probing AdS4/CFT3 proposals beyond chiral rings
We calculate the superconformal Witten index for the Chern-Simons-matter
theory which was proposed to describe multiple M2-branes on . We
consider a variant of this model, which exhibits explicit N=3 supersymmetry and
has the advantage of not having an exotic branch of the moduli space. At ,
we compare the index with that from the proposed gravity dual and find a
disagreement.Comment: references added; introduction modifie
Cartan-Weyl 3-algebras and the BLG Theory I: Classification of Cartan-Weyl 3-algebras
As Lie algebras of compact connected Lie groups, semisimple Lie algebras have
wide applications in the description of continuous symmetries of physical
systems. Mathematically, semisimple Lie algebra admits a Cartan-Weyl basis of
generators which consists of a Cartan subalgebra of mutually commuting
generators H_I and a number of step generators E^\alpha that are characterized
by a root space of non-degenerate one-forms \alpha. This simple decomposition
in terms of the root space allows for a complete classification of semisimple
Lie algebras. In this paper, we introduce the analogous concept of a
Cartan-Weyl Lie 3-algebra. We analyze their structure and obtain a complete
classification of them. Many known examples of metric Lie 3-algebras (e.g. the
Lorentzian 3-algebras) are special cases of the Cartan-Weyl 3-algebras. Due to
their elegant and simple structure, we speculate that Cartan-Weyl 3-algebras
may be useful for describing some kinds of generalized symmetries. As an
application, we consider their use in the Bagger-Lambert-Gustavsson (BLG)
theory.Comment: LaTeX. 34 pages.v2. deleted some distracting paragraphs in the
introduction to bring more out the main results of the paper. typos corrected
and references adde
Quantum finite-size effects for dyonic magnons in the AdS_4 x CP^3
We compute quantum corrections to finite-size effects for various dyonic
giant magnons in the AdS_4 x CP^3 in two different approaches. The off-shell
algebraic curve method is used to quantize the classical string configurations
in semi-classical way and to compute the corrections to the string energies.
These results are compared with the F-term L\"uscher formula based on the
S-matrix of the AdS_4 / CFT_3. The fact that the two results match exactly
provides another stringent test for the all-loop integrability conjecture and
the exact S-matrix based on it.Comment: 21 pages, No figures, corrected typos, added some reference
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