Davide Astolfi

Gauge invariant finite size spectrum of the giant magnon

It is shown that the finite size corrections to the spectrum of the giant magnon solution of classical string theory, computed using the uniform light-cone gauge, are gauge invariant and have physical meaning. This is seen in two ways: from a general argument where the single magnon is made gauge invariant by putting it on an orbifold as a wrapped state obeying the level matching condition as well as all other constraints, and by an explicit calculation where it is shown that physical quantum numbers do not depend on the uniform light-cone gauge parameter. The resulting finite size effects are exponentially small in the R-charge and the exponent (but not the prefactor) agrees with gauge theory computations using the integrable Hubbard model.

Finite-size corrections for quantum strings on {\text{Ad}}{{\text{S}}_4} \times \mathbb{C}{P^3}

We revisit the calculation of curvature corrections to the pp-wave energy of type IIA string states on

Full Lagrangian and Hamiltonian for quantum strings on AdS4 × CP3 in a near plane wave limit

{\text{Ad}}{{\text{S}}_4} \times \mathbb{C}{P^3}

Strings in AdS4 × \mathbb{C}{P^3} : finite size spectrum vs. Bethe Ansatz

initiated in arXiv:0807.1527. Using the near pp-wave Hamiltonian found in arXiv:0912.2257, we compute the first non-vanishing correction to the energy of a set of bosonic string states at order 1/R2, where R is the curvature radius of the background. The leading curvature corrections give rise to cubic, order 1/R, and quartic, order 1/R2, terms in the Hamiltonian, for which we implement the appropriate normal ordering prescription. Including the contributions from all possible fermionic and bosonic string states, we find that there exist logarithmic divergences in the sums over mode numbers which cancel between the cubic and quartic Hamiltonian. We show that from the form of the cubic Hamiltonian it is natural to require that the cutoff for summing over heavy modes must be twice the one for light modes. With this prescription the strong-weak coupling interpolating function h(λ), entering the magnon dispersion relation, does not receive a one-loop correction, in agreement with the algebraic curve spectrum. However, the single magnon dispersion relation exhibits finite-size exponential corrections.

Analysing wind farm efficiency on complex terrains

We find the full interacting Lagrangian and Hamiltonian for quantum strings in a near plane wave limit of AdS4 ×

Wind Power Forecasting techniques in complex terrain: ANN vs. ANN-CFD hybrid approach

\mathbb{C}

Advanced Data Mining Techniques for Power Performance Verification of an On-Shore Wind Farm

P3. The leading curvature corrections give rise to cubic and quartic terms in the Lagrangian and Hamiltonian that we compute in full. The Lagrangian is found as the type IIA Green-Schwarz superstring in the light-cone gauge employing a superspace construction with 32 grassmann-odd coordinates. The light-cone gauge for the fermions is non-trivial since it should commute with the supersymmetry condition. We provide a prescription to properly fix the κ-symmetry gauge condition to make it consistent with light-cone gauge. We use fermionic field redefinitions to find a simpler Lagrangian. To construct the Hamiltonian a Dirac procedure is needed in order to properly keep into account the fermionic second class constraints. We combine the field redefinition with a shift of the fermionic phase space variables that reduces Dirac brackets to Poisson brackets. This results in a completely well-defined and explicit expression for the full interacting Hamiltonian up to and including terms quartic in the number of fields.

A SCADA data mining method for precision assessment of performance enhancement from aerodynamic optimization of wind turbine blades

A bstractWe compute the first curvature corrections to the spectrum of light-cone gauge type IIA string theory that arise in the expansion of AdS4 ×