1,646 research outputs found
Nonlinear supratransmission in multicomponent systems
A method is proposed to solve the challenging problem of determining the
supratransmission threshold (onset of instability of harmonic boundary driving
inside a band gap) in multicomponent nonintegrable nonlinear systems. It is
successfully applied to the degenerate three-wave resonant interaction in a
birefringent quadratic medium where the process generates spatial gap solitons.
No analytic expression is known for this model showing the broad applicability
of the method to nonlinear systems.Comment: 4 pages, 3 figure
Convective instability induced by nonlocality in nonlinear diffusive systems
We consider a large class of nonlinear diffusive systems with nonlocal
coupling. By using a non-perturbative analytical approach we are able to
determine the convective and absolute instabilities of all the uniform states
of these systems. We find a huge window of convective instability that should
provide a great opportunity to study experimentally and theoretically noise
sustained patterns.Comment: 5 pages, accepted for publication in PR
SVD Entanglement Entropy
In this paper, we introduce a new quantity called SVD entanglement entropy.
This is a generalization of entanglement entropy in that it depends on two
different states, as in pre- and post-selection processes. This SVD
entanglement entropy takes non-negative real values and is bounded by the
logarithm of the Hilbert space dimensions. The SVD entanglement entropy can be
interpreted as the average number of Bell pairs distillable from intermediates
states. We observe that the SVD entanglement entropy gets enhanced when the two
states are in the different quantum phases in an explicit example of the
transverse-field Ising model. Moreover, we calculate the R{\'e}nyi SVD entropy
in various field theories and examine holographic calculations using the
AdS/CFT correspondence.Comment: 42 pages, 23 figure
Coordinated operation of electric vehicle charging and wind power generation as a virtual power plant: A multi-stage risk constrained approach
© 2019 Elsevier Ltd As the number of electric vehicles (EVs) is steadily increasing, their aggregation can offer significant storage to improve the electric system operation in many aspects. To this end, a comprehensive stochastic optimization framework is proposed in this paper for the joint operation of a fleet of EVs with a wind power producer (WPP) in a three-settlement pool-based market. An aggregator procures enough energy for the EVs based on their daily driving patterns, and schedules the stored energy to counterbalance WPP fluctuations. Different sources of uncertainty including the market prices and WPP generation are modeled through proper scenarios, and the risk is hedged by adding a risk measure to the formulation. To obtain more accurate results, the battery degradation costs are also included in the problem formulation. A detailed case study is presented based on the Iberian electricity market data as well as the technical information of three different types of EVs. The proposed approach is benchmarked against the disjoint operation of EVs and WPP. Numerical simulations demonstrate that the proposed strategy can effectively benefit EV owners and WPP by reducing the energy costs and increasing the profits
Macdonald operators and homological invariants of the colored Hopf link
Using a power sum (boson) realization for the Macdonald operators, we
investigate the Gukov, Iqbal, Kozcaz and Vafa (GIKV) proposal for the
homological invariants of the colored Hopf link, which include
Khovanov-Rozansky homology as a special case. We prove the polynomiality of the
invariants obtained by GIKV's proposal for arbitrary representations. We derive
a closed formula of the invariants of the colored Hopf link for antisymmetric
representations. We argue that a little amendment of GIKV's proposal is
required to make all the coefficients of the polynomial non-negative integers.Comment: 31 pages. Published version with an additional appendi
Convection-induced nonlinear-symmetry-breaking in wave mixing
We show that the combined action of diffraction and convection (walk-off) in
wave mixing processes leads to a nonlinear-symmetry-breaking in the generated
traveling waves. The dynamics near to threshold is reduced to a Ginzburg-Landau
model, showing an original dependence of the nonlinear self-coupling term on
the convection. Analytical expressions of the intensity and the velocity of
traveling waves emphasize the utmost importance of convection in this
phenomenon. These predictions are in excellent agreement with the numerical
solutions of the full dynamical model.Comment: 5 page
Surface Operator, Bubbling Calabi-Yau and AGT Relation
Surface operators in N=2 four-dimensional gauge theories are interesting
half-BPS objects. These operators inherit the connection of gauge theory with
the Liouville conformal field theory, which was discovered by Alday, Gaiotto
and Tachikawa. Moreover it has been proposed that toric branes in the A-model
topological strings lead to surface operators via the geometric engineering. We
analyze the surface operators by making good use of topological string theory.
Starting from this point of view, we propose that the wave-function behavior of
the topological open string amplitudes geometrically engineers the surface
operator partition functions and the Gaiotto curves of corresponding gauge
theories. We then study a peculiar feature that the surface operator
corresponds to the insertion of the degenerate fields in the conformal field
theory side. We show that this aspect can be realized as the geometric
transition in topological string theory, and the insertion of a surface
operator leads to the bubbling of the toric Calabi-Yau geometry.Comment: 36 pages, 14 figures. v2: minor changes and typos correcte
Generalized Borcea-Voisin Construction
C. Voisin and C. Borcea have constructed mirror pairs of families of
Calabi-Yau threefolds by taking the quotient of the product of an elliptic
curve with a K3 surface endowed with a non-symplectic involution. In this
paper, we generalize the construction of Borcea and Voisin to any prime order
and build three and four dimensional Calabi-Yau orbifolds. We classify the
topological types that are obtained and show that, in dimension 4, orbifolds
built with an involution admit a crepant resolution and come in topological
mirror pairs. We show that for odd primes, there are generically no minimal
resolutions and the mirror pairing is lost.Comment: 15 pages, 2 figures. v2: typos corrected & references adde
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