19,800 research outputs found
Eguchi-Kawai model with dynamical adjoint fermions
It is believed that fermions in adjoint representation on single site lattice
will restore the center symmetry, which is a crucial requirement for the volume
independence of large-N lattice gauge theories. We present a perturbative
analysis which supports the assumption for overlap fermions, but shows that
center symmetry is broken for naive fermions.Comment: 7 pages, 4 figures, Contribution to The XXVII International Symposium
on Lattice Field Theor
Lacunary Fourier series and a qualitative uncertainty principle for compact Lie groups
We define lacunary Fourier series on a compact connected semisimple Lie group
. If has lacunary Fourier series, and vanishes on a non empty
open set, then we prove that vanishes identically. This may be viewed as a
qualitative uncertainty principle
Truncated Overlap Fermions
In this talk I propose a new computational scheme with overlap fermions and a
fast algorithm to invert the corresponding Dirac operator.Comment: LATTICE99(algorithms
Asymptotics of Harish-Chandra expansions, bounded hypergeometric functions associated with root systems, and applications
A series expansion for Heckman-Opdam hypergeometric functions
is obtained for all
As a consequence, estimates for away from the walls of a Weyl
chamber are established. We also characterize the bounded hypergeometric
functions and thus prove an analogue of the celebrated theorem of Helgason and
Johnson on the bounded spherical functions on a Riemannian symmetric space of
the noncompact type. The -theory for the hypergeometric Fourier transform
is developed for . In particular, an inversion formula is proved when
struc2vec: Learning Node Representations from Structural Identity
Structural identity is a concept of symmetry in which network nodes are
identified according to the network structure and their relationship to other
nodes. Structural identity has been studied in theory and practice over the
past decades, but only recently has it been addressed with representational
learning techniques. This work presents struc2vec, a novel and flexible
framework for learning latent representations for the structural identity of
nodes. struc2vec uses a hierarchy to measure node similarity at different
scales, and constructs a multilayer graph to encode structural similarities and
generate structural context for nodes. Numerical experiments indicate that
state-of-the-art techniques for learning node representations fail in capturing
stronger notions of structural identity, while struc2vec exhibits much superior
performance in this task, as it overcomes limitations of prior approaches. As a
consequence, numerical experiments indicate that struc2vec improves performance
on classification tasks that depend more on structural identity.Comment: 10 pages, KDD2017, Research Trac
Implementation and validation of a wake model for vortex-surface interactions in low speed forward flight
The wake model was implemented using a VAX 750 and a Microvax II workstation. Online graphics capability using a DISSPLA graphics package. The rotor model used by Beddoes was significantly extended to include azimuthal variations due to forward flight and a simplified scheme for locating critical points where vortex elements are placed. A test case was obtained for validation of the predictions of induced velocity. Comparison of the results indicates that the code requires some more features before satisfactory predictions can be made over the whole rotor disk. Specifically, shed vorticity due to the azimuthal variation of blade loading must be incorporated into the model. Interactions between vortices shed from the four blades of the model rotor must be included. The Scully code for calculating the velocity field is being modified in parallel with these efforts to enable comparison with experimental data. To date, some comparisons with flow visualization data obtained at Georgia Tech were performed and show good agreement for the isolated rotor case. Comparison of time-resolved velocity data obtained at Georgia Tech also shows good agreement. Modifications are being implemented to enable generation of time-averaged results for comparison with NASA data
Disordered social media use and risky drinking in young adults:Differential associations with addiction-linked traits
Background Excessive or compulsive use of social media has been likened to an addiction, similar to other behavioural addictions such as pathological gambling or Internet addiction. This investigation sought to determine the degree to which personality traits associated with such disordered social media use overlap with those known to predict problematic substance use, with use of the most commonly abused legal substance alcohol as an example of the latter. Method Well‐known indices of disordered social media use, risky or problematic alcohol use, and the personality traits alexithymia, reward sensitivity, narcissism, and impulsivity were administered online to 143 men and women aged 18–35-years who were regular users of social media. The traits examined had previously been linked to substance misuse for a variety of substances, including alcohol, as presumed predisposing factors. Results After controlling for age, gender, and social desirability in hierarchical regressions, disordered social media use was predicted by narcissism, reward sensitivity, and impulsivity, whereas risky alcohol use was predicted by narcissism, alexithymia, and impulsivity. The ability of narcissism to predict disordered social media use was mediated by reward sensitivity, which was not the case for risky drinking. Conclusions Present results point to similarities and differences in addiction‐linked traits when comparing disordered social media use to risky or problematic substance use
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