21,426 research outputs found
The (11112) model on a 1+1 dimensional lattice
We study the chiral gauge model (11112) of four left-movers and one
right-mover with strong interactions in the 1+1 dimensional lattice. Exact
computations of relevant -matrix elements demonstrate a loophole that so
constructed model and its dynamics can possibly evade the ``no-go'' theorem of
Nielsen and Ninomiya.Comment: 15 pages, 1 fig. to appear in Phys. Rev.
Bounded Model Checking of State-Space Digital Systems: The Impact of Finite Word-Length Effects on the Implementation of Fixed-Point Digital Controllers Based on State-Space Modeling
The extensive use of digital controllers demands a growing effort to prevent
design errors that appear due to finite-word length (FWL) effects. However,
there is still a gap, regarding verification tools and methodologies to check
implementation aspects of control systems. Thus, the present paper describes an
approach, which employs bounded model checking (BMC) techniques, to verify
fixed-point digital controllers represented by state-space equations. The
experimental results demonstrate the sensitivity of such systems to FWL effects
and the effectiveness of the proposed approach to detect them. To the best of
my knowledge, this is the first contribution tackling formal verification
through BMC of fixed-point state-space digital controllers.Comment: International Symposium on the Foundations of Software Engineering
201
Non-Fermi liquid angle resolved photoemission lineshapes of Li0.9Mo6O17
A recent letter by Xue et al. (PRL v.83, 1235 ('99)) reports a Fermi-Liquid
(FL) angle resolved photoemission (ARPES) lineshape for quasi one-dimensional
Li0.9Mo6O17, contradicting our report (PRL v.82, 2540 ('99)) of a non-FL
lineshape in this material. Xue et al. attributed the difference to the
improved angle resolution. In this comment, we point out that this reasoning is
flawed. Rather, we find that their data have fundamental differences from other
ARPES results and also band theory.Comment: To be published as a PRL Commen
Liquid Crystal-Solid Interface Structure at the Antiferroelectric-Ferroelectric Phase Transition
Total Internal Reflection (TIR) is used to probe the molecular organization
at the surface of a tilted chiral smectic liquid crystal at temperatures in the
vicinity of the bulk antiferroelectric-ferroelectric phase transition. Data are
interpreted using an exact analytical solution of a real model for
ferroelectric order at the surface. In the mixture T3, ferroelectric surface
order is expelled with the bulk ferroelectric-antiferroelectric transition. The
conditions for ferroelectric order at the surface of an antiferroelectric bulk
are presented
The four fixed points of scale invariant single field cosmological models
We introduce a new set of flow parameters to describe the time dependence of
the equation of state and the speed of sound in single field cosmological
models. A scale invariant power spectrum is produced if these flow parameters
satisfy specific dynamical equations. We analyze the flow of these parameters
and find four types of fixed points that encompass all known single field
models. Moreover, near each fixed point we uncover new models where the scale
invariance of the power spectrum relies on having simultaneously time varying
speed of sound and equation of state. We describe several distinctive new
models and discuss constraints from strong coupling and superluminality.Comment: 24 pages, 6 figure
Implementing topological quantum manipulation with superconducting circuits
A two-component fermion model with conventional two-body interactions was
recently shown to have anyonic excitations. We here propose a scheme to
physically implement this model by transforming each chain of two two-component
fermions to the two capacitively coupled chains of superconducting devices. In
particular, we elaborate how to achieve the wanted operations to create and
manipulate the topological quantum states, providing an experimentally feasible
scenario to access the topological memory and to build the anyonic
interferometry.Comment: 4 pages with 3 figures; V2: published version with minor updation
Landau-Zener-Stuckelberg interference in a multi-anticrossing system
We propose a universal analytical method to study the dynamics of a
multi-anticrossing system subject to driving by one single large-amplitude
triangle pulse, within its time scales smaller than the dephasing time. Our
approach can explain the main features of the Landau-Zener-Stuckelberg
interference patterns recently observed in a tripartite system [Nature
Communications 1:51 (2010)]. In particular, we focus on the effects of the size
of anticrossings on interference and compare the calculated interference
patterns with numerical simulations. In addition, Fourier transform of the
patterns can extract information on the energy level spectrum.Comment: 6 pages, 5 figure
Heterogeneous feature space based task selection machine for unsupervised transfer learning
© 2015 IEEE. Transfer learning techniques try to transfer knowledge from previous tasks to a new target task with either fewer training data or less training than traditional machine learning techniques. Since transfer learning cares more about relatedness between tasks and their domains, it is useful for handling massive data, which are not labeled, to overcome distribution and feature space gaps, respectively. In this paper, we propose a new task selection algorithm in an unsupervised transfer learning domain, called as Task Selection Machine (TSM). It goes with a key technical problem, i.e., feature mapping for heterogeneous feature spaces. An extended feature method is applied to feature mapping algorithm. Also, TSM training algorithm, which is main contribution for this paper, relies on feature mapping. Meanwhile, the proposed TSM finally meets the unsupervised transfer learning requirements and solves the unsupervised multi-task transfer learning issues conversely
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