Quantum Dynamics on the Worldvolume from Classical su(n) Cohomology

A key symmetry of classical $p$-branes is invariance under worldvolume diffeomorphisms. Under the assumption that the worldvolume, at fixed values of the time, is a compact, quantisable K\"ahler manifold, we prove that the Lie algebra of volume-preserving diffeomorphisms of the worldvolume can be approximated by $su(n)$, for $n\to\infty$. We also prove, under the same assumptions regarding the worldvolume at fixed time, that classical Nambu brackets on the worldvolume are quantised by the multibrackets corresponding to cocycles in the cohomology of the Lie algebra $su(n)$.Comment: This is a contribution to the Special Issue on Deformation Quantization, published in SIGMA (Symmetry, Integrability and Geometry: Methods and Applications) at http://www.emis.de/journals/SIGMA

Z2Z4-additive cyclic codes, generator polynomials and dual codes

A ${\mathbb{Z}}_2{\mathbb{Z}}_4$-additive code ${\cal C}\subseteq{\mathbb{Z}}_2^\alpha\times{\mathbb{Z}}_4^\beta$ is called cyclic if the set of coordinates can be partitioned into two subsets, the set of ${\mathbb{Z}}_2$ and the set of ${\mathbb{Z}}_4$ coordinates, such that any cyclic shift of the coordinates of both subsets leaves the code invariant. These codes can be identified as submodules of the $\mathbb{Z}_4[x]$-module $\mathbb{Z}_2[x]/(x^\alpha-1)\times\mathbb{Z}_4[x]/(x^\beta-1)$. The parameters of a ${\mathbb{Z}}_2{\mathbb{Z}}_4$-additive cyclic code are stated in terms of the degrees of the generator polynomials of the code. The generator polynomials of the dual code of a ${\mathbb{Z}}_2{\mathbb{Z}}_4$-additive cyclic code are determined in terms of the generator polynomials of the code ${\cal C}$

Fiscal harmonization in the presence of public inputs

Fiscal harmonization for the European Union member states is a goal that encounters major difficulties for its implementation. Each country faces a particular trade-off between fiscal revenues generated by taxation and the productive efficiency loss induced by their respective tax code. Countries for which a particular harmonized tax code requires more taxation will have to face an increased efficiency loss, whereas those required to decrease their taxes will have to face a loss in fiscal revenue. This paper provides a quantitative measure of these trade-offs, for a number of taxes and for the European Union member states, using a DGE model with public inputs. Calibration of the model for the EU-15 member states gives us the following results: i) The maximum tax revenue level is not far away from the current tax levels for most countries, ii) The cases of Sweden, Denmark and Finland are anomalous, as productive efficiency can be gained by lowering tax rates without affecting fiscal revenues, iii) In general, countries would obtain efficiency gains without changing fiscal revenues by reducing the capital tax and increasing the labor tax and iv) Capital tax harmonization to the average capital tax rate can be done with quite small changes in both fiscal revenues and output for the majority of countries.Fiscal harmonization, applied general equilibrium

The current financial crisis: what should we learn from the great depressions of the Twentieth Century?

Studying the experience of countries that have experienced great depressions during the twentieth century teaches us that massive public interventions in the economy to maintain employment and investment during a financial crisis can, if they distort incentives enough, lead to a great depression.

Public debt frontiers: The greek case

Las causas de la crisis de deuda Griega son otras distintas de la indisciplina fiscal. Los indicadores macroeconómicos desde el año 200 a 2006 no indicaban nada que pudiera presagiar el desastre. Causas de tipo estratégico en el manejo de la deuda parecen más razonables a la hora de explicar el fenómenoUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

Public Debt Frontiers: The Greek Case

This paper attempts to quantify the maximum amount of debt that a government can sustain by itself, i.e., the limits to public indebtedness. Using a Dynamic General Equilibrium model where the government is fully characterized, we compute the steady state inverse relationship between the public debt to output ratio and the size of the government, measured as the total public expenditures to output ratio. This line is the budget constraint of a government in steady state. Calibration of the model for the Greek economy to fiscal targets reveals that, for the period just before the current recession, i.e. 2002-2006, the debt to GDP ratio was very close to the calculate limits wich depends dramatically on the interest rates. However, short after de financial crisis of 2008, sustained deficits drove the Greek economy to a point where the Greek Government crossed the debt limit where the country could only meet its debt obligations only if international investors where willing to lend. We conclude that the hight initial level of debts previous the crisis together with the rise in interest rates were the causes of the posterior debt crisis.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Union Games: Technological Unemployment

Given a production economy, we define a trade union game by considering strategic behavior on factor supplies. We refer to the Nash equilibria of this game as trade union equilibria. First we analyze situations under which unemployment of factors are supported as trade union equilibria. The degree of unemployment depends on technological conditions. In this line, we suggest a source of unemployment which differs from the usual sources provided in the related literature. Then, we state a limit result which shows that when the market power of trade unions decreases the corresponding sequence of trade union equilibria converges to the walrasian equilibrium, that is, to full employment of factors.Trade Union Games, unemployment, walrasian equilibrium, manipulability.

Synthesis and characterization of cationic polymer nanoparticles and investigation of their interaction with seroalbumin

Treballs Finals de Grau de Química, Facultat de Química, Universitat de Barcelona, Any: 2018, Tutors: Carlos María Müller Jevenois, Gabriela Calderó LinnhoffToday, a big pharmaceutical research effort is dedicated to controlled and targeted release of drugs. One of the most innovative options is the use of nanoparticles as non-viral vectors for the controlled and/or targeted release of drugs towards target organs or tissues. In these fields, the use of polymer nanoparticles is widespread due to their versatility: they can be easily functionalized (polymers have reactive terminal groups such as carboxylic acids or amines) and therefore they are easily targeted to certain tissues or organs. Moreover, given the high (and modulable) biodegradability of certain polymers such as poly(lactic acid) (PLA) or poly(lactic-coglycolic) acid (PLGA) the rate of drug release can be easily controlled. This work focuses on the preparation and characterization of polymer nanoparticles made of ethylcellulose and PLGA from template nano-emulsions. By the incorporation of a cationic surfactant in the formulation, positive surface charges were attained. Positively charged nanoparticles allow for strong electrostatic interactions with anionic molecules such as proteins, which could be interesting for the design of targeted and controlled drug release systems. Nano-emulsions were prepared by the PIC method using two slightly different techniques and were characterized by DLS (dynamic light scattering) and light transmittance versus time experiments. Nanoparticles were prepared by solvent evaporation and were characterized by DLS and Zpotential measurements. Their interaction with seroalbumin, the major protein in blood, was also studied through DLS and Z-potential measurements