Cascaded two-photon nonlinearity in a one-dimensional waveguide with multiple two-level emitters

We propose and theoretically investigate a model to realize cascaded optical nonlinearity with few atoms and photons in one-dimension (1D). The optical nonlinearity in our system is mediated by resonant interactions of photons with two-level emitters, such as atoms or quantum dots in a 1D photonic waveguide. Multi-photon transmission in the waveguide is nonreciprocal when the emitters have different transition energies. Our theory provides a clear physical understanding of the origin of nonreciprocity in the presence of cascaded nonlinearity. We show how various two-photon nonlinear effects including spatial attraction and repulsion between photons, background fluorescence can be tuned by changing the number of emitters and the coupling between emitters (controlled by the separation).Comment: 6 pages, 4 figure

Fractal Profit Landscape of the Stock Market

We investigate the structure of the profit landscape obtained from the most basic, fluctuation based, trading strategy applied for the daily stock price data. The strategy is parameterized by only two variables, p and q. Stocks are sold and bought if the log return is bigger than p and less than -q, respectively. Repetition of this simple strategy for a long time gives the profit defined in the underlying two-dimensional parameter space of p and q. It is revealed that the local maxima in the profit landscape are spread in the form of a fractal structure. The fractal structure implies that successful strategies are not localized to any region of the profit landscape and are neither spaced evenly throughout the profit landscape, which makes the optimization notoriously hard and hypersensitive for partial or limited information. The concrete implication of this property is demonstrated by showing that optimization of one stock for future values or other stocks renders worse profit than a strategy that ignores fluctuations, i.e., a long-term buy-and-hold strategy.Comment: 12 pages, 4 figure

Flavor SU(3) analysis of charmless B->PP decays

We perform a global fits to charmless $B \to PP$ decays which independently constrain the $(\bar\rho,\bar\eta)$ vertex of the unitarity triangle. The fitted amplitudes and phase are used to predict the branching ratios and CP asymmetries of all decay modes, including those of the $B_s$ system. Different schemes of SU(3) breaking in decay amplitude sizes are analyzed. The possibility of having a new physics contribution to $K \pi$ decays is also discussed.Comment: 3 pages, 2 figs. Talk given at EPS-HEP07 To appear in the proceedings, Reference adde

Habitus e inserciones laborales en personas trans : posibilidades objetivas hechas cuerpo

Proponemos el abordaje de la cuestión laboral en personas trans, superando la clásica correspondencia entre travestismo y trabajo sexual. Para esto, nos servimos de la matriz analítica bourdieusiana, a partir de la cual las tendencias a buscar y encontrar empleo se dan en función de la incorporación de las posibilidades objetivas de los agentes en cuestión. Los habitus, como realidad objetiva hecha cuerpo, condicionan las aspiraciones que tienen los sujetos y, a su vez, guían sus estrategias laborales en dirección de encontrar respuesta a sus expectativas, dándose consciente o inconscientemente una correspondencia entre deseos y posibilidades objetivas. En este marco proponemos un repaso de las supuestos teóricos y metodológicos de la Teoría de la práctica de Pierre Bourdieu (I-II) para luego aproximarnos a un análisis de las estrategias sociales de reproducción en personas trans a través de una de sus variables más determinantes: el trabajo (III-IV).Fil: Heredia Baek, Gabriela . Universidad Nacional de Córdob

Essential dimension of simple algebras in positive characteristic

Let $p$ be a prime integer, $1\leq s\leq r$ integers, $F$ a field of characteristic $p$. Let \cat{Dec}_{p^r} denote the class of the tensor product of $r$ $p$-symbols and \cat{Alg}_{p^r,p^s} denote the class of central simple algebras of degree $p^r$ and exponent dividing $p^s$. For any integers $s<r$, we find a lower bound for the essential $p$-dimension of \cat{Alg}_{p^r,p^s}. Furthermore, we compute upper bounds for \cat{Dec}_{p^r} and \cat{Alg}_{8,2} over $\ch(F)=p$ and $\ch(F)=2$, respectively. As a result, we show \ed_{2}(\cat{Alg}_{4,2})=\ed(\cat{Alg}_{4,2})=\ed_{2}(\gGL_{4}/\gmu_{2})=\ed(\gGL_{4}/\gmu_{2})=3 and 3\leq \ed(\cat{Alg}_{8,2})=\ed(\gGL_{8}/\gmu_{2})\leq 10 over a field of characteristic 2.Comment: Any comments are welcom