Evolutive, iterative aerodynamical global optimization, with weak aerodynamics/ structure interactions

The aerodynamical global optimization (GO) of the shape of a flying configuration (FC) leads to an extended variational problem with free boundaries. An own evolutive iterative optimum-optimorum (OO) theory was developed in order to solve this enlarged variational problem inside of a class of admissible FCs, defined by some chosen properties. An inviscid, GO shape of FC is used only in its first step of iteration. This shape is checked by using hybrid numerical solutions of the Navier-Stokes layer (NSL). The friction drag coefficient is determined and a control of the inviscid GO shape of FC, for the structure point of view, is performed. New and/or modified initial constraints can occur, due to the interactions aerodynamics/ structure. In the second step of the iterative OO-theory, migrations in the drag functional (which is now the total drag) and in the constraints are performed

Multipoint global optimal shape design by morphing

The determination of the global optimized (GO) shape of a flying configuration (FC), which is of minimum drag at two cruising Mach numbers, can be obtained by morphing. Two movable leading edge flaps are used for this purpose. They are retracted at higher Mach number and stretched by the lower one. Two consecutive enlarged variational problems with free boundaries occur and are solved by using the own iterative optimumoptimorum theory as optimization strategy. It uses only in its first step of iteration hyperbolic potential solutions and determine the inviscid GO shape of FC as surrogate model. Up the second step of iteration own hybrid solutions for Navier-Stokes layer are used and the total drag is the new functional

Surrogate models for the iterative Optimum-Optimorum theory and their applications

The author has developed non-classical three-dimensional hyperbolic analytic so­lutions (HASs) for the axial disturbance velocities over several flying configurations (FCs) in supersonic flow. The lift, pitching moment. inviscid drag coefficients and the distributions of pressure coefficients on FCs, at moderate angles of attack, can be rapid computed. The HASs are also used as start solutions for the design of inviscid, global optimized (GO) shapes of FCs, by using the own optimum-optimorum strategy. These inviscid GO shapes are proposed as surrogate models and arc used in the first step of an iterative optimum-opti­ morum theory. Up the second step of iterations the HASs are replaced by hybrid analytic­ numeric solutions for the Navier-Stokes layer and the friction drag coefficient is computed

Global optimal design of two aerospace vehicles

A variant of Saenger project is proposed . It is composed of two global optimized and fully- integrated models namely a suborbital small one LEO in form of Catamaran almost blended with two central fuselages almost embeded in the wing thickness and a greater one geostationary one GEO also in form of Catamaran almost blended with two fuselages almost embeded in the wing thickness but located almost parallel to the leading edges, far from the central part of the wing in order to allow the up and go of the LEO in its central part

Consistent SO(6) Reduction Of Type IIB Supergravity on S^5

Type IIB supergravity can be consistently truncated to the metric and the self-dual 5-form. We obtain the complete non-linear Kaluza-Klein S^5 reduction Ansatz for this theory, giving rise to gravity coupled to the fifteen Yang-Mills gauge fields of SO(6) and the twenty scalars of the coset SL(6,R)/SO(6). This provides a consistent embedding of this subsector of N=8, D=5 gauged supergravity in type IIB in D=10. We demonstrate that the self-duality of the 5-form plays a crucial role in the consistency of the reduction. We also discuss certain necessary conditions for a theory of gravity and an antisymmetric tensor in an arbitrary dimension D to admit a consistent sphere reduction, keeping all the massless fields. We find that it is only possible for D=11, with a 4-form field, and D=10, with a 5-form. Furthermore, in D=11 the full bosonic structure of eleven-dimensional supergravity is required, while in D=10 the 5-form must be self-dual. It is remarkable that just from the consistency requirement alone one would discover D=11 and type IIB supergravities, and that D=11 is an upper bound on the dimension.Comment: Latex, 14 pages, typos corrected and comments adde

Abelian-Higgs and Vortices from ABJM: towards a string realization of AdS/CMT

We present ans\"{a}tze that reduce the mass-deformed ABJM model to gauged Abelian scalar theories, using the fuzzy sphere matrices $G^\alpha$. One such reduction gives a Toda system, for which we find a new type of nonabelian vortex. Another gives the standard Abelian-Higgs model, thereby allowing us to embed all the usual (multi-)vortex solutions of the latter into the ABJM model. By turning off the mass deformation at the level of the reduced model, we can also continuously deform to the massive $\phi^4$ theory in the massless ABJM case. In this way we can embed the Landau-Ginzburg model into the AdS/CFT correspondence as a consistent truncation of ABJM. In this context, the mass deformation parameter $\mu$ and a field VEV $$ act as $g$ and $g_c$ respectively, leading to a well-motivated AdS/CMT construction from string theory. To further this particular point, we propose a simple model for the condensed matter field theory that leads to an approximate description for the ABJM abelianization. Finally, we also find some BPS solutions to the mass-deformed ABJM model with a spacetime interpretation as an M2-brane ending on a spherical M5-brane.Comment: 43 pages, latex, explanations added in the introduction, end of section 4, and on page 2

Comments on gluon 6-point scattering amplitudes in N=4 SYM at strong coupling

We use the AdS/CFT prescription of Alday and Maldacena \cite{am} to analyze gluon 6-point scattering amplitudes at strong coupling in ${\cal N}=4$ SYM. By cutting and gluing we obtain AdS 6-point amplitudes that contain extra boundary conditions and come close to matching the field theory results. We interpret them as parts of the field theory amplitudes, containing only certain diagrams. We also analyze the collinear limits of 6- and 5-point amplitudes and discuss the results.Comment: 35 pages, 7 figures, latex, references adde

Naturalistic stimuli reveal a dominant role for agentic action in visual representation

Abstract Naturalistic, dynamic movies evoke strong, consistent, and information-rich patterns of activity over a broad expanse of cortex and engage multiple perceptual and cognitive systems in parallel. The use of naturalistic stimuli enables functional brain imaging research to explore cognitive domains that are poorly sampled in highly-controlled experiments. These domains include perception and understanding of agentic action, which plays a larger role in visual representation than was appreciated from experiments using static, controlled stimuli

Topological mass in seven dimensions and dualities in four dimensions

The massive topologically and self dual theories en seven dimensions are considered. The local duality between these theories is established and the dimensional reduction lead to the different dualities for massive antisymmetric fields in four dimensions.Comment: 7 page