686 research outputs found
Non-holomorphic multi-matrix gauge invariant operators based on Brauer algebra
We present an orthogonal basis of gauge invariant operators constructed from
some complex matrices for the free matrix field, where operators are expressed
with the help of Brauer algebra. This is a generalisation of our previous work
for a signle complex matrix. We also discuss the matrix quantum mechanics
relevant to N=4 SYM on S^{3} times R. A commuting set of conserved operators
whose eigenstates are given by the orthogonal basis is shown by using enhanced
symmetries at zero coupling.Comment: 29 pages, typos corrected, references adde
Atomic masses of intermediate-mass neutron-deficient nuclei with relative uncertainty down to 35-ppb via multireflection time-of-flight mass spectrograph
High-precision mass measurements of Cu, Zn, Ga,
Ge, As, Br, Rb, and Sr were performed
utilizing a multireflection time-of-flight mass spectrograph combined with the
gas-filled recoil ion separator GARIS-II. In the case of Ga, a mass
uncertainty of 2.1 keV, corresponding to a relative precision of , was obtained and the mass value is in excellent agreement
with the 2016 Atomic Mass Evaluation. For Ge and Br, where masses
were previously deduced through indirect measurements, discrepancies with
literature values were found. The feasibility of using this device for mass
measurements of nuclides more neutron-deficient side, which have significant
impact on the -process pathway, is discussed.Comment: 15 pages, 6 figures, 1 tabl
Beyond the Planar Limit in ABJM
In this article we consider gauge theories with a U(N)X U(N) gauge group. We
provide, for the first time, a complete set of operators built from scalar
fields that are in the bi fundamental of the two groups. Our operators
diagonalize the two point function of the free field theory at all orders in
1/N. We then use this basis to investigate non-planar anomalous dimensions in
the ABJM theory. We show that the dilatation operator reduces to a set of
decoupled harmonic oscillators, signaling integrability in a nonplanar large N
limit.Comment: v2: minor revisison
Surprisingly Simple Spectra
The large N limit of the anomalous dimensions of operators in
super Yang-Mills theory described by restricted Schur polynomials, are studied.
We focus on operators labeled by Young diagrams that have two columns (both
long) so that the classical dimension of these operators is O(N). At large N
these two column operators mix with each other but are decoupled from operators
with columns. The planar approximation does not capture the large N
dynamics. For operators built with 2, 3 or 4 impurities the dilatation operator
is explicitly evaluated. In all three cases, in a certain limit, the dilatation
operator is a lattice version of a second derivative, with the lattice emerging
from the Young diagram itself. The one loop dilatation operator is diagonalized
numerically. All eigenvalues are an integer multiple of and there
are interesting degeneracies in the spectrum. The spectrum we obtain for the
one loop anomalous dimension operator is reproduced by a collection of harmonic
oscillators. This equivalence to harmonic oscillators generalizes giant
graviton results known for the BPS sector and further implies that the
Hamiltonian defined by the one loop large dilatation operator is
integrable. This is an example of an integrable dilatation operator, obtained
by summing both planar and non-planar diagrams.Comment: 34 page
Branes, Anti-Branes and Brauer Algebras in Gauge-Gravity duality
We propose gauge theory operators built using a complex Matrix scalar which
are dual to brane-anti-brane systems in , in the zero
coupling limit of the dual Yang-Mills. The branes involved are half-BPS giant
gravitons. The proposed operators dual to giant-anti-giant configurations
satisfy the appropriate orthogonality properties. Projection operators in
Brauer algebras are used to construct the relevant multi-trace Matrix
operators. These are related to the ``coupled representations'' which appear in
2D Yang-Mills theory. We discuss the implications of these results for the
quantum mechanics of a complex matrix model, the counting of non-supersymmetric
operators and the physics of brane-anti-brane systems. The stringy exclusion
principle known from the properties of half-BPS giant gravitons, has a new
incarnation in this context. It involves a qualitative change in the map
between brane-anti-brane states to gauge theory operators. In the case of a
pair of sphere giant and anti-giant this change occurs when the sum of the
magnitudes of their angular momenta reaches .Comment: 52 pages, 10 figure
On the Open-Closed B-Model
We study the coupling of the closed string to the open string in the
topological B-model. These couplings can be viewed as gauge invariant
observables in the open string field theory, or as deformations of the
differential graded algebra describing the OSFT. This is interpreted as an
intertwining map from the closed string sector to the deformation (Hochschild)
complex of the open string algebra. By an explicit calculation we show that
this map induces an isomorphism of Gerstenhaber algebras on the level of
cohomology. Reversely, this can be used to derive the closed string from the
open string. We shortly comment on generalizations to other models, such as the
A-model.Comment: LaTeX, 48 pages. Citation adde
Magnetic Properties in Non-centrosymmetric Superconductors with and without Antiferromagnetic Order
The paramagnetic properties in non-centrosymmetric superconductors with and
without antiferromagnetic (AFM) order are investigated with focus on the heavy
Fermion superconductors, CePt_3Si, CeRhSi_3 and CeIrSi_3. First, we investigate
the spin susceptibility in the linear response regime and elucidate the role of
AFM order. The spin susceptibility at T=0 is independent of the pairing
symmetry and increases in the AFM state. Second, the non-linear response to the
magnetic field are investigated on the basis of an effective model for CePt_3Si
which may be also applicable to CeRhSi_3 and CeIrSi_3. The role of
antisymmetric spin-orbit coupling (ASOC), helical superconductivity,
anisotropic Fermi surfaces and AFM order are examined in the dominantly s-, p-
and d-wave states. We emphasize the qualitatively important role of the mixing
of superconducting (SC) order parameters in the p-wave state which enhances the
spin susceptibility and suppresses paramagnetic depairing effect in a
significant way. Therefore, the dominantly p-wave superconductivity admixed
with the s-wave order parameter is consistent with the paramagnetic properties
of CePt_3Si at ambient pressure. We propose some experiments which can
elucidate the novel pairing states in CePt_3Si as well as CeRhSi_3 and
CeIrSi_3.Comment: To appear in J. Phys. Soc. Jpn. (2007) No.1
Anomalous Spin Response in Non-centrosymmetric Compounds
We examine static spin susceptibilities of spin
components and in the non-centrosymmetric tetragonal
system. These show anomalous momentum dependences like and , which vanish in centrosymmetric systems. The magnitudes of
the anomalous spin susceptibilities are enhanced by the on-site Coulomb
interaction, especially, around an ordering wave vector. The significant and
anomalous momentum dependences of these susceptibilities are explained by a
group theoretical analysis. As the direct probe of the anomalous spin
susceptibility, we propose a polarized neutron scattering experiment.Comment: 4 pages, 1 table, 4 figure
Nonplanar integrability at two loops
In this article we compute the action of the two loop dilatation operator on
restricted Schur polynomials that belong to the su(2) sector, in the displaced
corners approximation. In this non-planar large N limit, operators that
diagonalize the one loop dilatation operator are not corrected at two loops.
The resulting spectrum of anomalous dimensions is related to a set of decoupled
harmonic oscillators, indicating integrability in this sector of the theory at
two loops. The anomalous dimensions are a non-trivial function of the 't Hooft
coupling, with a spectrum that is continuous and starting at zero at large N,
but discrete at finite N.Comment: version to appear in JHE
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