3,661 research outputs found
Bound states of PT-symmetric separable potentials
All of the PT-symmetric potentials that have been studied so far have been
local. In this paper nonlocal PT-symmetric separable potentials of the form
, where is real, are examined.
Two specific models are examined. In each case it is shown that there is a
parametric region of the coupling strength for which the PT symmetry
of the Hamiltonian is unbroken and the bound-state energies are real. The
critical values of that bound this region are calculated.Comment: 10 pages, 3 figure
Brief Note Preliminary Studies of the Vocal Responses of Territorial Cardinals (Cardinalis Cardinalis) to Songs of a Strange Male
Author Institution: Department of Zoology, Miami Universit
The Three-User Finite-Field Multi-Way Relay Channel with Correlated Sources
This paper studies the three-user finite-field multi-way relay channel, where
the users exchange messages via a relay. The messages are arbitrarily
correlated, and the finite-field channel is linear and is subject to additive
noise of arbitrary distribution. The problem is to determine the minimum
achievable source-channel rate, defined as channel uses per source symbol
needed for reliable communication. We combine Slepian-Wolf source coding and
functional-decode-forward channel coding to obtain the solution for two classes
of source and channel combinations. Furthermore, for correlated sources that
have their common information equal their mutual information, we propose a new
coding scheme to achieve the minimum source-channel rate.Comment: Author's final version (accepted and to appear in IEEE Transactions
on Communications
On codimension two flats in Fermat-type arrangements
In the present note we study certain arrangements of codimension flats in
projective spaces, we call them "Fermat arrangements". We describe algebraic
properties of their defining ideals. In particular, we show that they provide
counterexamples to an expected containment relation between ordinary and
symbolic powers of homogeneous ideals.Comment: 9 page
Resonator/zero-Qubit architecture for superconducting qubits
We analyze the performance of the Resonator/zero-Qubit (RezQu) architecture
in which the qubits are complemented with memory resonators and coupled via a
resonator bus. Separating the stored information from the rest of the
processing circuit by at least two coupling steps and the zero qubit state
results in a significant increase of the ON/OFF ratio and the reduction of the
idling error. Assuming no decoherence, we calculate such idling error, as well
as the errors for the MOVE operation and tunneling measurement, and show that
the RezQu architecture can provide high fidelity performance required for
medium-scale quantum information processing.Comment: 11 pages, 5 figure
S-Track Stabilization of Heterotic de Sitter Vacua
We present a new mechanism, the S-Track, to stabilize the volume modulus S in
heterotic M-theory flux compactifications along with the orbifold-size T
besides complex structure and vector bundle moduli stabilization. The key
dynamical ingredient which makes the volume modulus stabilization possible, is
M5-instantons arising from M5-branes wrapping the whole Calabi-Yau slice. These
are natural in heterotic M-theory where the warping shrinks the Calabi-Yau
volume along S^1/Z_2. Combined with H-flux, open M2-instantons and hidden
sector gaugino condensation it leads to a superpotential W which stabilizes S
similar like a racetrack but without the need for multi gaugino condensation.
Moreover, W contains two competing non-perturbative effects which stabilize T.
We analyze the potential and superpotentials to show that it leads to heterotic
de Sitter vacua with broken supersymmetry through non-vanishing F-terms.Comment: 16 pages, 2 figures; final PRD versio
Some Notes on the Early History of the Robert B. Gordon Natural Area for Environmental Studies
The Finite Field Multi-Way Relay Channel with Correlated Sources: The Three-User Case
The three-user finite field multi-way relay channel with correlated sources
is considered. The three users generate possibly correlated messages, and each
user is to transmit its message to the two other users reliably in the Shannon
sense. As there is no direct link among the users, communication is carried out
via a relay, and the link from the users to the relay and those from the relay
to the users are finite field adder channels with additive noise of arbitrary
distribution. The problem is to determine the set of all possible achievable
rates, defined as channel uses per source symbol for reliable communication.
For two classes of source/channel combinations, the solution is obtained using
Slepian-Wolf source coding combined with functional-decode-forward channel
coding.Comment: to be presented at ISIT 201
Diffusing proteins on a fluctuating membrane: Analytical theory and simulations
Using analytical calculations and computer simulations we consider both the
lateral diffusion of a membrane protein and the fluctuation spectrum of the
membrane in which the protein is embedded. The membrane protein interacts with
the membrane shape through its spontaneous curvature and bending rigidity. The
lateral motion of the protein may be viewed as diffusion in an effective
potential, hence, the effective mobility is always reduced compared to the case
of free diffusion. Using a rigorous path-integral approach we derive an
analytical expression for the effective diffusion coefficient for small ratios
of temperature and bending rigidity, which is the biologically relevant limit.
Simulations show very good quantitative agreement with our analytical result.
The analysis of the correlation functions contributing to the diffusion
coefficient shows that the correlations between the stochastic force of the
protein and the response in the membrane shape are responsible for the
reduction.
Our quantitative analysis of the membrane height correlation spectrum shows
an influence of the protein-membrane interaction causing a distinctly altered
wave-vector dependence compared to a free membrane. Furthermore, the time
correlations exhibit the two relevant timescales of the system: that of
membrane fluctuations and that of lateral protein diffusion with the latter
typically much longer than the former. We argue that the analysis of the
long-time decay of membrane height correlations can thus provide a new means to
determine the effective diffusion coefficient of proteins in the membrane.Comment: 12 pages, 8 figure
Innovation und Technologischer Wandel in Österreich
Series: Discussion Papers of the Institute for Economic Geography and GIScienc
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