Branes from Light: Embeddings and Energetics for Symmetric kk-Quarks in N=4\mathcal{N}=4 SYM

We construct the D3-brane dual to a $k$-quark of $\mathcal{N}=4$ super-Yang-Mills theory in the totally symmetric representation of $SU(N)$, undergoing arbitrary motion. Our method of construction generalizes previous work by Mikhailov, and proceeds by shooting light rays inward from the anti-de Sitter boundary, to trace out the brane embedding. We expect this method to have wider relevance, and provide evidence for this by showing that it correctly reproduces the known D5-brane embeddings dual to totally antisymmetric $k$-quarks. As an application of our solutions, we compute the energy of the D3-brane and extract from it the $k$-quark's intrinsic energy and rate of radiation. The result matches expectations based on previous calculations, and makes contact with the exact Bremsstrahlung function for the fundamental representation.Comment: 1+28 pages, 3 figures. v2: references adde

Deterministic hierarchical networks

It has been shown that many networks associated with complex systems are small-world (they have both a large local clustering coefficient and a small diameter) and they are also scale-free (the degrees are distributed according to a power law). Moreover, these networks are very often hierarchical, as they describe the modularity of the systems that are modeled. Most of the studies for complex networks are based on stochastic methods. However, a deterministic method, with an exact determination of the main relevant parameters of the networks, has proven useful. Indeed, this approach complements and enhances the probabilistic and simulation techniques and, therefore, it provides a better understanding of the systems modeled. In this paper we find the radius, diameter, clustering coefficient and degree distribution of a generic family of deterministic hierarchical small-world scale-free networks that has been considered for modeling real-life complex systems

Semiclassical description of the kinematically complete experiments

Based on the semiclassical, impact parameter method a theoretical model is constructed to calculate totally differential cross sections for single ionization of helium by impact with fast C$^{6+}$ ions. Good agreement with the experiment is achieved in the scattering plane, while in the perpendicular plane a similar structure to that observed experimentally is obtained. The contribution of different partial waves to the cross section is also investigated.Comment: 9 pages, 6 figure

The spectra of Manhattan street networks

AbstractThe multidimensional Manhattan street networks constitute a family of digraphs with many interesting properties, such as vertex symmetry (in fact they are Cayley digraphs), easy routing, Hamiltonicity, and modular structure. From the known structural properties of these digraphs, we determine their spectra, which always contain the spectra of hypercubes. In particular, in the standard (two-dimensional) case it is shown that their line digraph structure imposes the presence of the zero eigenvalue with a large multiplicity

Influence of Recycled Precast Concrete Aggregate on Durability of Concrete's Physical Processes

ABSTRACT: The research presented in this article analysed the influence of incorporating precast concrete waste as an alternative to coarse aggregate in self-compacting concrete to generate new precast elements. The experimental study involved the characterization of recycled aggregate and the design of the mix of the new self-compacting concrete (SCC). The experimental study evaluates the physical processes that affect the durability of concrete with percentages of incorporation such as 20%, 50% and 100% of recycled aggregate. Two types of SCC were manufactured with minimum compressive strength of 30 MPa and 45 MPa. The properties analysed were density of hardened SCC, shrinkage cracking, freeze-thaw resistance, resistance to ageing by thermal shock and abrasion resistance. The results obtained were compared with those of the control concrete, observing great capacity of the SCC under physical aggressions that affect durability. The results of this research show that it is possible to use the recycled aggregate coming from precast pieces in order to the manufacture of self-compacting recycled concrete in the same precast industry. However, high loss of proprieties occurs for a 100% substitution, while for 20% and 50%, the variations with respect to control concrete are smaller. In addition, taking advantage of this waste to incorporate it back into the production chain contributes to more sustainable construction.This research was funded by Junta de Castilla y León (Regional Government) for funding UIC-231 through project BU119P17; MINECO for funding through project BIA2014-55576-C2-1-R; FEDER (European Regional Development Funds) and LADICI

The influence of recycled aggregates from precast elements on the mechanical properties of structural self-compacting concrete

Recycled Aggregates (RA) from structural precast elements and the performance of Self-Compacting Concrete (SCC) containing RA in percentage substitutions of 20%, 50% and 100% are described in this paper. Three Control Concretes (CC-30, CC-37.5, CC-45) manufactured with Natural Aggregates (NA), and their corresponding Recycled Aggregate Concretes (RAC-20, RAC-50, RAC-100) are evaluated in terms of physical and mechanical properties. The in-fresh properties results (flowability, viscosity and passing ability) of the RAC were suitable for their use as SSC. Furthermore, the tests of compressive, splitting tensile and flexural strength, as well as density, porosity, water absorption, ultrasonic pulse velocity, stiffness, and both dynamic and static modulus provided results close to those of the SCC with NA, and in compliance with the requirements of current regulations. The recycling process that takes place in the precast factory supposes an economical improvement and an important contribution to global sustainability, in accordance with the concept of the circular economy.The authors wish to express their gratitude for having contributed to the financing of this research to: Junta de Castilla y León (Regional Government) for funding UIC-231 through project BU119P17; MINECO for funding through project BIA2014-55576-C2-1-R; and FEDER (European Regional Development Funds). Moreover, we are grateful to the precast concrete company Artepref for having collaborated with the present research work

Entropy Maximization in the Presence of Higher-Curvature Interactions

Within the context of the entropic principle, we consider the entropy of supersymmetric black holes in N=2 supergravity theories in four dimensions with higher-curvature interactions, and we discuss its maximization at points in moduli space at which an excess of hypermultiplets becomes massless. We find that the gravitational coupling function F^(1) enhances the maximization at these points in moduli space. In principle, this enhancement may be modified by the contribution from higher F^(g)-couplings. We show that this is indeed the case for the resolved conifold by resorting to the non-perturbative expression for the topological free energy.Comment: 22 pages, 8 figures, AMS-LaTe

Quivers via anomaly chains

We study quivers in the context of matrix models. We introduce chains of generalized Konishi anomalies to write the quadratic and cubic equations that constrain the resolvents of general affine and non-affine quiver gauge theories, and give a procedure to calculate all higher-order relations. For these theories we also evaluate, as functions of the resolvents, VEV's of chiral operators with two and four bifundamental insertions. As an example of the general procedure we explicitly consider the two simplest quivers A2 and A1(affine), obtaining in the first case a cubic algebraic curve, and for the affine theory the same equation as that of U(N) theories with adjoint matter, successfully reproducing the RG cascade result.Comment: 32 pages, latex; typos corrected, published versio