56,678 research outputs found
A parallel algorithm for the enumeration of benzenoid hydrocarbons
We present an improved parallel algorithm for the enumeration of fixed
benzenoids B_h containing h hexagonal cells. We can thus extend the enumeration
of B_h from the previous best h=35 up to h=50. Analysis of the associated
generating function confirms to a very high degree of certainty that and we estimate that the growth constant and the amplitude .Comment: 14 pages, 6 figure
More Holographic Berezinskii-Kosterlitz-Thouless Transitions
We find two systems via holography that exhibit quantum
Berezinskii-Kosterlitz-Thouless (BKT) phase transitions. The first is the ABJM
theory with flavor and the second is a flavored (1,1) little string theory. In
each case the transition occurs at nonzero density and magnetic field. The BKT
transition in the little string theory is the first example of a quantum BKT
transition in (3+1) dimensions. As in the "original" holographic BKT transition
in the D3/D5 system, the exponential scaling is destroyed at any nonzero
temperature and the transition becomes second order. Along the way we construct
holographic renormalization for probe branes in the ABJM theory and propose a
scheme for the little string theory. Finally, we obtain the embeddings and
(half of) the meson spectrum in the ABJM theory with massive flavor.Comment: 24 pages, 5 figure
Reconsidering "the love of art" : evaluating the potential of art museum outreach
Art museums have long been identified as bastions of social and cultural exclusion. This conclusion was best evidenced by the large-scale 1967 French study by Bourdieu and Darbel demonstrating the exclusionary nature of “The Love of Art.” However, in recent years there have been increasing efforts to reach out to a broader range of visitors beyond conventional
audiences. The present study investigates the impacts of an outreach program at a UK art museum, which sought to engage socially excluded young mothers. This study employs ethnographic research methods on a longitudinal basis to develop qualitative insights about the program seeking to mitigate cultural exclusion. While the study’s findings uphold many longstanding critiques of art museums’ conventional approaches, the study also indicates that carefully designed outreach activities can overcome such limitations and enhance cultural
engagement. Thus, art museums’ limited appeal is tied to problematic public engagement practices that can be changed
Effective interactions and the nuclear shell-model
This review aims at a critical discussion of the interplay between effective
interactions derived from various many-body approaches and spectroscopic data
extracted from large scale shell-model studies. To achieve this, our many-body
scheme starts with the free nucleon-nucleon (NN) interaction, typically
modelled on various meson exchanges. The NN interaction is in turn renormalized
in order to derive an effective medium dependent interaction. The latter is in
turn used in shell-model calculations of selected nuclei. We also describe how
to sum up the parquet class of diagrams and present initial uses of the
effective interactions in coupled cluster many-body theory.Comment: 61 pages, submitted to Prog. Part. Nucl. Phy
Jets in strongly-coupled N = 4 super Yang-Mills theory
We study jets of massless particles in N=4 super Yang-Mills using the AdS/CFT
correspondence both at zero and finite temperature. We set up an initial state
corresponding to a highly energetic quark/anti-quark pair and follow its time
evolution into two jets. At finite temperature the jets stop after traveling a
finite distance, whereas at zero temperature they travel and spread forever. We
map out the corresponding baryon number charge density and identify the generic
late time behavior of the jets as well as features that depend crucially on the
initial conditions.Comment: 21 pages, 12 figures. Added discussion regarding string profiles in
more than one spatial dimension. Refs adde
Tunable effective g-factor in InAs nanowire quantum dots
We report tunneling spectroscopy measurements of the Zeeman spin splitting in
InAs few-electron quantum dots. The dots are formed between two InP barriers in
InAs nanowires with a wurtzite crystal structure grown by chemical beam
epitaxy. The values of the electron g-factors of the first few electrons
entering the dot are found to strongly depend on dot size and range from close
to the InAs bulk value in large dots |g^*|=13 down to |g^*|=2.3 for the
smallest dots. These findings are discussed in view of a simple model.Comment: 4 pages, 3 figure
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