Langevin dynamics of financial systems: a second-order analysis

We address the issue of stock market fluctuations within Langevin Dynamics (LD) and the thermodynamics definitions of multifractality in order to study its second-order characterization given by the analogous specific heat C_{q}, where q is an analogous temperature relating the moments of the generating partition function for the financial data signals. Due to non-linear and additive noise terms within the LD, we found that C_{q} can display a shoulder to the right of its main peak as also found in the S&P500 historical data which may resemble a classical phase transition at a critical point.Comment: LaTex, 4 PostScript figures; To appear EJP-

Conflict, Claim and Contradiction in the New Indigenous State of Bolivia

Recent conflict between indigenous people and a self-styled indigenous state in Bolivia has brought to the fore some of the paradoxes and contradictions within the concept of indigeneity itself. The contemporary politics of state sponsored indigeneity in Bolivia has as much capacity to create new inequalities as it does to address old ones and there is a conceptual deficit in understanding contemporary indigenous rights claims, in particular, as they relate to the state. I reject Peter Geschiere?s (2009) suggestion that one should distinguish between ?autochthony? and ?indigeneity? but am inspired by these arguments to suggest that one needs to make a critical distinction between the kinds of claims different indigenous people make against the state. Of interest here are the consequences of indigeneity being transformed from being a language of resistance to a language of governance. I propose a conceptual distinction between inclusive national indigeneity for the majority which seeks to co-opt the state through accessing the language of governance and a minority concept of indigeneity which needs protection from the state and continues to use indigeneity as a language of resistance. Only by looking at the kinds of claims people make through the rhetoric of indigeneity can we make sense of the current indigenous conflict in Bolivia and elsewhere

Stock Market and Motion of a Variable Mass Spring

We establish an analogy between the motion of spring whose mass increases linearly with time and volatile stock markets dynamics within an economic model based on simple temporal demand and supply functions [J. Phys. A: Math. Gen. 33, 3637 (2000)]. The total system energy E_t is shown to be proportional to a decreasing time dependent spring constant k_t. This model allows to derive log-periodicity cos[log (t-t_{c})] on commodity prices and oscillations (surplus and shortages) in the level of stocks. We also made an attempt to connect these results to the Tsallis statistics parameter q based on a possible force-entropy correlation [Physica A 341, 165 (2004)] and find that the Tsallis second entropic term \sum_{i=1}^{W} p_i^{q}/(q-1) relates to the square of the demand (or supply) function

A possible scenario for volumetric display through nanoparticle suspensions

We discuss on the potential of suspensions of gold nanoparticles with variable refractive index for the possible physical realization of in-relief virtual dynamic display of plane images. A reasoning approach for a vision system to display in real-time volumetric moving images is proposed based on well-known properties of optical media, namely the anomalous dispersion of light on certain transparent media and the virtual image formed by a refracting transparent surface. The system relies on creating mechanisms to modify the refractive index of in-relief virtual dynamical display (iVDD) bulbs that ideally would contain a suspension of gold nanoparticles each and that might be ordered in an array filling up a whole screen.Comment: 15 pages. To appear Momento - Revista de Fisica (June 2001