Semidiscretization and long-time asymptotics of nonlinear diffusion equations

We review several results concerning the long time asymptotics of nonlinear diffusion models based on entropy and mass transport methods. Semidiscretization of these nonlinear diffusion models are proposed and their numerical properties analysed. We demonstrate the long time asymptotic results by numerical simulation and we discuss several open problems based on these numerical results. We show that for general nonlinear diffusion equations the long-time asymptotics can be characterized in terms of fixed points of certain maps which are contractions for the euclidean Wasserstein distance. In fact, we propose a new scaling for which we can prove that this family of fixed points converges to the Barenblatt solution for perturbations of homogeneous nonlinearities for values close to zero.

La Llémena : història, paisatge i natura

Creació d’una ruta a la Vall del Llémena que uneixi els quatre nuclis municipals: Sant Gregori, Canet d’Adri, Sant Martí de Llémena i Sant Aniol de Finestres per tal de fomentar un turisme més sostenible i promocionar el patrimoni cultural, històric i natural de la Vall

Poison without antidote for the historical Socrates and french classical tragedy in El verí del teatre (The Poison of the Theatre) by Rodolf Sirera. (An extreme dose of sadism to put a stop to the excesses of theatrical fiction).

Socrates' serene attitude before his death -although this is questioned-, as described by Xenophon in his Apologia Socratis becomes for the playwright Rodolf Sirera a useful reference in an effort to reflect boldly on the limits of theatrical fiction in another clear example of the Classical Tradition, including that derived from Baroque Tragedy. However, in this case, it is judged severely to make us more conscious of the risk of turning life into a mere theatrical performance and human beings into actors and actresses in a play they did not write.

Verí sense antídot per al Sòcrates històric i la tragèdia barroca al Verí del teatre de Rodolf Sirera. (Una dosi extrema de sadisme per aturar els excessos de la ficció teatral).

Socrates' serene attitude before his death -although this is questioned-, as described by Xenophon in his Apologia Socratis becomes for the playwright Rodolf Sirera a useful reference in an effort to reflect boldly on the limits of theatrical fiction in another clear example of the Classical Tradition, including that derived from Baroque Tragedy. However, in this case, it is judged severely to make us more conscious of the risk of turning life into a mere theatrical performance and human beings into actors and actresses in a play they did not write.

Una visió de la Guerra de Successió des de l'exili: el 'Teatro de desdichas' (Milà, 1716)

El 1716 es publicà a Milà un text que fa una àmplia justificació històrica i política de la causa de Carles III d'Àustria a la Guerra de Successió d'Espanya (1702-1715). L'obra, de dimensions considerables (72 pàgines), va ser redactada per un eclesiàstic castellà que participà a la defensa de Barcelona durant el darrer setge i que va ser desterrat a Itàlia per les noves autoritats borbòniques. L'article analitza algunes de les idees centrals del text, com ara: l'oposició a la tirania borbònica i la defensa d'una monarquia moderada; la identificació de l'entronització de Felip V com el trencament de l'equilibri europeu i el punt culminant de la decadència d'Espanya; la denúncia de la traïció dels aliats; la vindicació de l'austriacisme castellà i la crítica al borbonisme d'alguns sectors catalans; i la descripció de la repressió i de l'exili.

On the multiwavelength spectrum of the microquasar 1E1740.7-2942

The microquasar 1E 1740.7-2942 is a source located in the direction of the Galactic Center. It has been detected at X-rays, soft gamma-rays, and in the radio band, showing an extended radio component in the form of a double-sided jet. Although no optical counterpart has been found so far for 1E 1740.7-2942, its X-ray activity strongly points to a galactic nature. Aims.We aim to improve our understanding of the hard X-ray and gamma-ray production in the system, exploring whether the jet can emit significantly at high energies under the light of the present knowledge. Methods.We have modeled the source emission, from radio to gamma-rays, with a cold-matter dominated jet model. INTEGRAL data combined with radio and RXTE data, as well as EGRET and HESS upper-limits, are used to compare the computed and the observed spectra. Results.From our modeling, we find out that jet emission cannot explain the high fluxes observed at hard X-rays without violating at the same time the constraints from the radio data, favoring the corona origin of the hard X-rays. Also, 1E 1740.7-2942 might be detected by GLAST or AGILE at GeV energies, and by HESS and HESS-II beyond 100 GeV, with the spectral shape likely affected by photon-photon absorption in the disk and corona photon fields.

Veneno sin antídoto para el Sócrates histórico y la Tragedia Barroca en El verí del teatre (El veneno del teatro) de Rodolf Sirera. (Una dosis extrema de sadismo para atajar los excesos de la ficción teatral)

[spa] Sócrates y su serena actitud ante la muerte –si bien cuestionándola-, según relato de Jenofonte en su Apología de Sócrates, se convierten para el dramaturgo Rodolf Sirera en la referencia idónea para una reflexión osada sobre los límites de la ficción teatral. Tradición Clásica, pues –incluida la que proviene de la Tragedia Barroca-, sometida a un juicio severo en aras de una mayor conciencia del peligro de reducir la vida a una mera representación y a los seres humanos en intérpretes forzados de un guión que no escribieron.