First Law, Counterterms and Kerr-AdS_5 Black Holes

We apply the counterterm subtraction technique to calculate the action and other quantities for the Kerr--AdS black hole in five dimensions using two boundary metrics; the Einstein universe and rotating Einstein universe with arbitrary angular velocity. In both cases, the resulting thermodynamic quantities satisfy the first law of thermodynamics. We point out that the reason for the violation of the first law in previous calculations is that the rotating Einstein universe, used as a boundary metric, was rotating with an angular velocity that depends on the black hole rotation parameter. Using a new coordinate system with a boundary metric that has an arbitrary angular velocity, one can show that the resulting physical quantities satisfy the first law.Comment: 19 pages, 1 figur

RANKING OF SEISMIC ZONES IN GREECE USING MEASURES OF NETWORKS FORMED FROM EARTHQUAKE HISTORICAL DATA

Επιχειρείται διερεύνηση των αλληλεξαρτήσεων μεταξύ σεισμών μεInterdependencies in earthquakes wit

Online Admission Control and Embedding of Service Chains

The virtualization and softwarization of modern computer networks enables the definition and fast deployment of novel network services called service chains: sequences of virtualized network functions (e.g., firewalls, caches, traffic optimizers) through which traffic is routed between source and destination. This paper attends to the problem of admitting and embedding a maximum number of service chains, i.e., a maximum number of source-destination pairs which are routed via a sequence of to-be-allocated, capacitated network functions. We consider an Online variant of this maximum Service Chain Embedding Problem, short OSCEP, where requests arrive over time, in a worst-case manner. Our main contribution is a deterministic O(log L)-competitive online algorithm, under the assumption that capacities are at least logarithmic in L. We show that this is asymptotically optimal within the class of deterministic and randomized online algorithms. We also explore lower bounds for offline approximation algorithms, and prove that the offline problem is APX-hard for unit capacities and small L > 2, and even Poly-APX-hard in general, when there is no bound on L. These approximation lower bounds may be of independent interest, as they also extend to other problems such as Virtual Circuit Routing. Finally, we present an exact algorithm based on 0-1 programming, implying that the general offline SCEP is in NP and by the above hardness results it is NP-complete for constant L.Comment: early version of SIROCCO 2015 pape

A Critical State Evaluation of Fines Effect on Liquefaction Potential

Published results from laboratory tests show that an increase in the percentage of fines generally leads to a reduction of the cyclic liquefaction resistance of a sand, while empirical correlations from in-situ tests consider the presence of fines as beneficial. In order to study this seemingly not univocal effect of tines content, this paper involves the integrated framework of Critical State Soil Mechanics. For this purpose, firstly the effect of tines on the location of the Critical State Line (CSL) is studied through statistical analysis of a large data set of triaxial element tests. Results show that fines affect the CSL location in the (e-lnp) space, but not its slope in (p-q) space. In particular, an increase of fines content practically leads to a clockwise rotation of the CSL in (e-lnp) space. Introducing this finding as a mere change in parameter values of an appropriate Critical State constitutive model, simulations of cyclic undrained triaxial tests were performed. These simulations show that the presence of fines is beneficial at relatively small effective stresses, i.e. the stresses prevailing at liquefiable layers in-situ. Furthermore, these simulations show that the effect is reversed at relatively large effective stresses, i.e. the stresses usually considered in laboratory tests

Anatomy of bubbling solutions

We present a comprehensive analysis of holography for the bubbling solutions of Lin-Lunin-Maldacena. These solutions are uniquely determined by a coloring of a 2-plane, which was argued to correspond to the phase space of free fermions. We show that in general this phase space distribution does not determine fully the 1/2 BPS state of N=4 SYM that the gravitational solution is dual to, but it does determine it enough so that vevs of all single trace 1/2 BPS operators in that state are uniquely determined to leading order in the large N limit. These are precisely the vevs encoded in the asymptotics of the LLM solutions. We extract these vevs for operators up to dimension 4 using holographic renormalization and KK holography and show exact agreement with the field theory expressions.Comment: 67 pages, 6 figures; v2: typos corrected, refs added; v3: expanded explanations, more typos correcte

Exact Gravity Dual of a Gapless Superconductor

A model of an exact gravity dual of a gapless superconductor is presented in which the condensate is provided by a charged scalar field coupled to a bulk black hole of hyperbolic horizon in asymptotically AdS spacetime. Below a critical temperature, the black hole acquires its hair through a phase transition while an electromagnetic perturbation of the background Maxwell field determines the conductivity of the boundary theory.Comment: 21 pages, 8 figures, a section on the stability of the MTZ black hole is added, references are added, version to be published in JHE

Effect of methyl jasmonate and sucrose on endogenous non-structural carbohydrates in petals and leaves of cut ‘First Red’ roses (Rosa hybrida L.)

Effects of exogenously applied methyl jasmonate (MeJA) and sucrose on vase life and non-structural carbohydrate concentration in petals and leaves of cut ‘First Red’ roses were investigated. Roses were placed in sealed plastic containers and received MeJA vapour treatment (0.1 μL MeJA L-1) for 24 h at 20°C. Flowers were then placed in individual bottles containing 0 or 2% (v/v) sucrose solution. Flower petals and the two uppermost five-leaflet leaves were detached on days 0, d 5 and d 10 of vase life. Samples were individually snap-frozen in liquid nitrogen and freeze-dried. Non-structural carbohydrates were extracted and quantified using standard HPLC coupled to evaporative light scattering detection. The MeJA vapour treatment enhanced vase life of flower and foliage of ‘First Red’ roses. Significant differences were observed between foliage life of cut ‘First Red’ roses that were treated with MeJA and sucrose, but not for flower life. Rose stems treated with MeJA in the absence of sucrose had an extended vase life compared to roses treated with 2% sucrose alone (14.0 vs. 12.8 days of vase life). Sucrose and myo-inositol, and to a lesser extent glucose concentrations in petals of cut roses decreased during vase life, even when flowers were supplied with 2% sucrose. Concomitant to this, fructose levels in petals increased during vase life. Neither sucrose nor MeJA had a significant effect on any of the sugars measured in petals of cut roses. In contrast, significant differences were apparent for all sugars measured in leaves that were treated with MeJA and sucrose solutions. The combination of MeJA and 2% sucrose solution sharply increased endogenous sucrose concentration in leaves, but the opposite was shown in the absence of 2% sucrose. Sucrose treatment alone did not consistently alter endogenous sucrose concentration. Interactions between MeJA and sucrose on sugar metabolism are discussed

The Growth of Transplanted Tumours in Mice after Chronic Inhalation of Fresh Cigarette Smoke

The subcutaneous growth of the Lewis lung tumour in C57BL mice chronically exposed to fresh cigarette smoke was increased above that in age-matched control mice. When murine sarcoma virus (Harvey) induced tumour cells were introduced to the lungs of groups of BALB/c mice, only mice chronically exposed to fresh cigarette smoke died with tumour cells in the lungs. Tumour cell growth in mice during short term cigarette smoke exposure was indistinguishable from that in controls