Hemeroteca del mes enero, 2012

Monoidal categories in, and linking, geometry and algebra

Por • 25 ene, 2012 • Category: Opinion

This is a report on aspects of the theory and use of monoidal categories. The first section introduces the main concepts through the example of the category of vector spaces. String notation is explained and shown to lead naturally to a link between knot theory and monoidal categories. The second section reviews the light thrown on aspects of representation theory by the machinery of monoidal category theory, such as braidings and convolution. The category theory of Mackey functors is reviewed in the third section. Some recent material and a conjecture concerning monoidal centres is included. The fourth and final section looks at ways in which monoidal categories are, and might, be used for new invariants of low-dimensional manifolds and for the field theory of theoretical physics.



The Eurasian Triple Entente: Touch Iran in a War, You Will Hear Russia and China

Por • 24 ene, 2012 • Category: Internacionales

Despite the areas of difference and the rivalries between Moscow and Tehran, Russian and Iranian ties are increasing. Both Russia and Iran share many commonalities. They are both major energy exporters, have deeply seated interests in the South Caucasus, oppose NATO’s missile shield, and want to keep the U.S. and E.U. from controlling the energy corridors around the Caspian Sea Basin. Moscow and Tehran also share many of the same allies, from Armenia, Tajikistan, and Belarus to Syria and Venezuela. Yet, above all things, both republics are also two of Washington’s main geo-strategic targets. With the inclusion of the Chinese, the Russian Federation and Iran are widely considered to be allies and partners. Together the Russia Federation, the People’s Republic of China, and the Islamic Republic of Iran form a barrier against the United States. The three form this through a triple alliance that is the core of a Eurasian coalition resisting Washington’s encroachment into Eurasia and America’s quest for global hegemony.



On current situation in Syria

Por • 24 ene, 2012 • Category: Política

The current situation in Syria remains one of the most important components of the Middle Eastern and international policies. Using Syria’s domestic crisis and pursuing their own goals NATO’s leading states, Israel, Turkey and the monarchies of the Persian Gulf are trying to undermine the Syrian regime. Since the beginning of the crisis in Syria I have made two trips to that country as a member of international delegations in August 2011 and in January 2012. If we watch the dynamics of situation’s development over that period on the one hand we can state intensification of terrorist groups in Syria and on the other hand we see a broader people’s support of President Bashar Assad and a clear demarcation of political forces’ positions.



How Peircean was the “‘Fregean’ Revolution” in Logic?

Por • 24 ene, 2012 • Category: Crítica

The historiography of logic conceives of a Fregean revolution in which modern mathematical logic (also called symbolic logic) has replaced Aristotelian logic. The preeminent expositors of this conception are Jean van Heijenoort (1912-1986) and Donald Angus Gillies. The innovations and characteristics that comprise mathematical logic and distinguish it from Aristotelian logic, according to this conception, created ex nihlo by Gottlob Frege (1848-1925) in his Begriffsschrift of 1879, and with Bertrand Russell (1872-1970) as its chief This position likewise understands the algebraic logic of Augustus De Morgan (1806-1871), George Boole (1815-1864), Charles Sanders Peirce (1838-1914), and Ernst Schr\”oder (1841-1902) as belonging to the Aristotelian tradition. The “Booleans” are understood, from this vantage point, to merely have rewritten Aristotelian syllogistic in algebraic guise.



The semantic conception of proof

Por • 24 ene, 2012 • Category: Filosofía

We analyze the informal semantic conception of proof and axiomatize the proof relation and the provability operator. A self referential propositional calculus which admits provable liar type sentences is introduced and proven consistent. We also investigate the problem of interpreting arbitrary formal systems in systems which include a provability operator.



La industrialización sustitutiva

Por • 19 ene, 2012 • Category: Nacionales

Fuese como fuese, la industrialización sustitutiva produjo resultados durante años



Proyectos de PEI

Por • 19 ene, 2012 • Category: Nacionales

El ministro de Ciencia anunció que venía de aprobar 365 Proyectos PEI. Adicionalmente, informó que el año pasado destinó 54 millones para el pago del estipendio PEI, a una taza unitaria de BsF 642 mensuales para cada miembro



The myth of an “isolated’ Iran

Por • 18 ene, 2012 • Category: Internacionales

It’s not at all far-fetched to imagine hardcore full-spectrum dominance practitioners inside the Pentagon riding a false-flag incident in the Persian Gulf to an attack on Iran (or simply using it to pressure Tehran into a fatal miscalculation). Consider as well the new US military strategy just unveiled by President Barack Obama in which the focus of Washington’s attention is to move from two failed ground wars in the Greater Middle East to the Pacific (and so to China). Iran happens to be right in the middle, in Southwest Asia, with all that oil heading toward an energy-hungry modern Middle Kingdom over waters guarded by the US Navy. So yes, this larger-than-life psychodrama we call “Iran” may turn out to be as much about China and the US dollar as it is about the politics of the Persian Gulf or Iran’s non-existent bomb. The question is: What rough beast, its hour come round at last, slouches towards Beijing to be born?



Red lines in the Strait of Hormuz

Por • 18 ene, 2012 • Category: Política

We find ourselves in a situation in which neither side wants to force the other into extreme steps and neither side is in a position to enter into broader accommodations. And that’s what makes the situation dangerous. When fundamental issues are at stake, each side is in a position to profoundly harm the other if pressed, and neither side is in a position to negotiate a broad settlement, a long game of chess ensues. And in that game of chess, the possibilities of miscalculation, of a bluff that the other side mistakes for an action, are very real. Ideology aside – and the United States negotiating with the “axis of evil” or Iran with the “Great Satan” would be tough sells to their respective domestic audiences – the problem with this is that it is difficult to see what each has to offer the other. Europe and China are redefining the way the world works. But kingdoms run on oil, as someone once said, and a lot of oil comes through Hormuz. Iran may or may not be able to close the strait, and that reshapes Europe and China. The New Year thus begins where we expected: at the Strait of Hormuz.



Chávez considera “absurdo” la posible sanción de EE UU a los países que recibieron a Ahmadineyad

Por • 17 ene, 2012 • Category: Nacionales

Defendió que estos países son “libres” y apuntó que “allá los Estados Unidos que tiene esa pretensión”. “No van a poder. El imperio norteamericano terminará siendo lo que decía Mao (Tse-tung): un imperio de papel y nosotros pequeños tigres de acero, pero tigres de acero y de acero, además. Para allá vamos”, concluyó.