6,113 research outputs found
Yang-Baxter equation for the asymmetric eight-vertex model
In this note we study `a la Baxter [1] the possible integrable manifolds of
the asymmetric eight-vertex model. As expected they occur when the Boltzmann
weights are either symmetric or satisfy the free-fermion condition but our
analysis clarify the reason both manifolds need to share a universal invariant.
We also show that the free-fermion condition implies three distinct classes of
integrable models.Comment: Latex, 12 pages, 1 figur
Budget-restricted utility games with ordered strategic decisions
We introduce the concept of budget games. Players choose a set of tasks and
each task has a certain demand on every resource in the game. Each resource has
a budget. If the budget is not enough to satisfy the sum of all demands, it has
to be shared between the tasks. We study strategic budget games, where the
budget is shared proportionally. We also consider a variant in which the order
of the strategic decisions influences the distribution of the budgets. The
complexity of the optimal solution as well as existence, complexity and quality
of equilibria are analyzed. Finally, we show that the time an ordered budget
game needs to convergence towards an equilibrium may be exponential
Spectral Functions in Holographic Renormalization Group Flows
The spectrum of two-point functions in a holographic renormalization group
flow from an ultraviolet (UV) to an infrared (IR) conformal fixed point is
necessarily continuous. For a toy model, the spectral function does not only
show the expected UV and IR behaviours, but other interesting features such as
sharp peaks and oscillations in the UV. The spectral functions for the
SU(3)xU(1) flow in AdS_4/CFT_3 and the SU(2)xU(1) flow in AdS_5/CFT_4 are
calculated numerically. They exhibit a simple cross-over behaviour and
reproduce the conformal dimensions of the dual operators in the UV and IR
conformal phases.Comment: 20 pages, 6 figures v2: added referene
Volatile Sulfur Compounds in Foods as a Result of Ionizing Radiation
Ionizing radiation improves food safety and extends shelf life by inactivating food-borne pathogens and spoilage microorganisms. However, irradiation may induce the development of an off-odor, particularly at high doses. The off-odor has been called “irradiation odor”. Substantial evidence suggests that volatile sulfur compounds (VSCs) play an important role in the development of the off-odor. These compounds include hydrogen sulfide, methanethiol, methyl sulfide, dimethyl disulfide and dimethyl trisulfide among others. The formation of off-odor and VSCs due to irradiation in meat, and fruit juices is presented. It is known that irradiation exerts its effect through radiolysis of water in foods where water is a dominant component. Irradiation of water produces three primary free radicals: hydroxyl, hydrogen atoms, and hydrated electrons. Use of specific scavengers in a model system revealed that hydroxyl radicals are involved in the formation of VSCs. Possible mechanisms for formation of VSC are also discussed. Also discussed are possible remedies for formation of VSCs and off-odor, such as use of antioxidants and double packaging
N=2 Supersymmetric SO(N)/Sp(N) Gauge Theories from Matrix Model
We use the matrix model to describe the N=2 SO(N)/Sp(N) supersymmetric gauge
theories with massive hypermultiplets in the fundamental representation. By
taking the tree level superpotential perturbation made of a polynomial of a
scalar chiral multiplet, the effective action for the eigenvalues of chiral
multiplet can be obtained. By varying this action with respect to an
eigenvalue, a loop equation is obtained. By analyzing this equation, we derive
the Seiberg-Witten curve within the context of matrix model.Comment: 14pp;v2 refs added, clarified in page 4, 6 and 11 and the sign of
resolvent corrected;v3 improved in page 5 and 6 and the flavor dependent part
in the integration around P added and to appear in PR
Optically Driven Qubits in Artificial Molecules
We present novel models of quantum gates based on coupled quantum dots in
which a qubit is regarded as the superposition of ground states in each dot.
Coherent control on the qubit is performed by both a frequency and a
polarization of a monochromatic light pulse illuminated on the quantum dots. We
also show that a simple combination of two single qubit gates functions as a
controlled NOT gate resulting from an electron-electron interaction. To examine
the decoherence of quantum states, we discuss electronic relaxation contributed
mainly by LA phonon processes.Comment: 11 pages, 4 figures, submitted to Physical Review
Self-consistent non-Markovian theory of a quantum state evolution for quantum information processing
It is shown that the operator sum representation for non-Markovian dynamics
and the Lindblad master equation in Markovian limit can be derived from a
formal solution to quantum Liouville equation for a qubit system in the
presence of decoherence processes self-consistently. Our formulation is the
first principle theory based on projection-operator formalism to obtain an
exact reduced density operator in time-convolutionless form starting from the
quantum Liouville equation for a noisy quantum computer. The advantage of our
approach is that it is general enough to describe a realistic quantum computer
in the presence of decoherence provided details of the Hamiltonians are known.Comment: 5page
Orbiting Membranes in M-theory on AdS_7 x S^4 Background
We study classical solutions describing rotating and boosted membranes on
AdS_7 x S^4 background in M-theory. We find the dependence of the energy on the
spin and R-charge of these solutions. In the flat space limit we get E ~
S^{2/3}, while for AdS at leading order E-S grows as S^{1/3}. The membranes on
AdS_4 x S^7 background have briefly been studied as well.Comment: 13 pages, latex, v2: a note and refs. added, some typos correcte
Resolving the M2-brane
We construct deformed, T^2 wrapped, rotating M2-branes on a resolved cone
over Q^{1,1,1} and Q^{1,1,1}/Z_2, as well as on a product of two Eguchi-Hanson
instantons. All worldvolume directions of these supersymmetric and regular
solutions are fibred over the transverse space. These constitute gravity duals
of D=3, N=2 gauge theories. In particular, the deformed M2-brane on a resolved
cone over Q^{1,1,1} and the S^1 wrapped M2-brane on a resolved cone over
Q^{1,1,1}/Z_2 provide explicit realizations of holographic renormalization
group flows in M-theory for which both conformal and Lorentz symmetries are
broken in the IR region and restored in the UV limit. These solutions can be
dualized to supersymmetric type IIB pp-waves, which are rendered non-singular
either by additional flux or a twisted time-like direction.Comment: Latex, 23 pages, references adde
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