1,883 research outputs found
Refined Counting of Necklaces in One-loop SYM
We compute the grand partition function of SYM at one-loop in
the sector with general chemical potentials, extending the results of
P\'olya's theorem. We make use of finite group theory, applicable to all orders
of expansion. We show that only the planar terms contribute to the
grand partition function, which is therefore equal to the grand partition
function of an ensemble of XXX spin chains. We discuss how Hagedorn
temperature changes on the complex plane of chemical potentials.Comment: 34 pages, v2: typo corrected, v3: added a subsection about finite Nc,
to appear in JHE
Negative anomalous dimensions in N=4 SYM
We elucidate aspects of the one-loop anomalous dimension of -singlet
multi-trace operators in SYM at finite . First,
we study how corrections lift the large degeneracy of the
spectrum, which we call the operator submixing problem. We observe that all
large zero modes acquire non-positive anomalous dimension starting at
order , and they mix only among the operators with the same number of
traces at leading order. Second, we study the lowest one-loop dimension of
operators of length equal to . The dimension of such operators becomes
more negative as increases, which will eventually diverge in a double
scaling limit. Third, we examine the structure of level-crossing at finite
in view of unitarity. Finally we find out a correspondence between the
large zero modes and completely symmetric polynomials of Mandelstam
variables.Comment: 34+31 pages, many figures, a Mathematica file attached, v2: typos
corrected, references added, section 5 revised, v3: revised Section 4 on
correlators, and small detail
Transfer Characteristics in Graphene Field-Effect Transistors with Co Contacts
Graphene field-effect transistors with Co contacts as source and drain
electrodes show anomalous distorted transfer characteristics. The anomaly
appears only in short-channel devices (shorter than approximately 3
micrometers) and originates from a contact-induced effect. Band alteration of a
graphene channel by the contacts is discussed as a possible mechanism for the
anomalous characteristics observed.Comment: 10 pages, 3 figures, Appl. Phys. Let
Five-loop Konishi from the Mirror TBA
We use the Thermodynamic Bethe Ansatz equations for the AdS_5 \times S^5
mirror model to derive the five-loop anomalous dimension of the Konishi
operator. We show numerically that the corresponding result perfectly agrees
with the one recently obtained via the generalized Luscher formulae. This
constitutes an important test of the AdS/CFT TBA system.Comment: 14 pages, 2 figures, v2: published versio
Large Winding Sector of AdS/CFT
We study a family of classical strings on R x S^3 subspace of the AdS_5 x S^5
background that interpolates between pulsating strings and single-spike
strings. They are obtained from the helical strings of hep-th/0609026 by
interchanging worldsheet time and space coordinates, which maps
rotating/spinning string states with large spins to oscillating states with
large winding numbers. From a finite-gap perspective, this transformation is
realised as an interchange of quasi-momentum and quasi-energy defined for the
algebraic curve. The gauge theory duals are also discussed, and are identified
with operators in the non-holomorphic sector of N=4 super Yang-Mills. They can
be viewed as excited states above the ``antiferromagnetic'' state, which is
``the farthest from BPS'' in the spin-chain spectrum. Furthermore, we
investigate helical strings on AdS_3 x S^1 in an appendix.Comment: 1+52 pages, 10 figures, v2: references and comments added, v3: minor
changes and a reference adde
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