Novel electric field effects on Landau levels in Graphene

A single graphene layer exhibits an anomalous Landau level spectrum. A massless Dirac like low energy electronic spectrum underlies this anomaly. We study, analytically and numerically, the effect of a uniform electric field $(E)$ on the anomalous Landau levels. We solve the problem exactly within the Dirac cone approximation and find an interesting scaling of the spectrum, leading to the collapse of the Landau levels at a critical $E_c(B)$, for a given magnetic field $B$. We offer a physical interpretation of our result, which uses `graphene relativity' and the boost operation. Electric fields, non-uniform at nanoscopic ($\sim l_c$, magnetic) length scales, produce local collapse at $E < E_c$. We expect an anomalous breakdown of quantum Hall states in real graphene, induced by large Hall currents.Comment: 4 pages, 3 figure

Local Search in Unstructured Networks

We review a number of message-passing algorithms that can be used to search through power-law networks. Most of these algorithms are meant to be improvements for peer-to-peer file sharing systems, and some may also shed some light on how unstructured social networks with certain topologies might function relatively efficiently with local information. Like the networks that they are designed for, these algorithms are completely decentralized, and they exploit the power-law link distribution in the node degree. We demonstrate that some of these search algorithms can work well on real Gnutella networks, scale sub-linearly with the number of nodes, and may help reduce the network search traffic that tends to cripple such networks.Comment: v2 includes minor revisions: corrections to Fig. 8's caption and references. 23 pages, 10 figures, a review of local search strategies in unstructured networks, a contribution to `Handbook of Graphs and Networks: From the Genome to the Internet', eds. S. Bornholdt and H.G. Schuster (Wiley-VCH, Berlin, 2002), to be publishe

Searching for the Sunk Cost Fallacy

We seek to isolate in the laboratory factors that encourage and discourage the sunk cost fallacy. Subjects play a computer game in which they decide whether to keep digging for treasure on an island or to sink a cost (which will turn out to be either high or low) to move to another island. The research hypothesis is that subjects will stay longer on islands that were more costly to find. Nine treatment variables are considered, e.g. alternative visual displays, whether the treasure value of an island is shown on arrival or discovered by trial and error, and alternative parameters for sunk costs. The data reveal a surprisingly small and erratic sunk cost effect that is generally insensitive to the proposed psychological drivers.sunk cost fallacy, experimental economics

Global Warming and Climate Change: a Critique on International Law and Policy

Global warming and climate change, a multidisciplinary topic is a matter of International concern. There are some International environmental treaties related to global warming and climate change. The most significant International agreement in this area is - UNFCCC - the United Nations Framework Convention on Climate Change adopted at the Rio Earth Summit in 1992 and ratified by 195 countries. It mainly deals with greenhouse gases emissions mitigation, adaptation and finance starting in the year 2020. The Kyoto Protocol which extends the 1992 UNFCC mandates State Parties to reduce greenhouse gas emissions: its two basic premises are - global warming exists, and human-made CO2 emissions caused global warming. The Kyoto Protocol came into force in 2005 and each COP has served as the ‘meeting of parties' to Kyoto Protocol such as COP13 (Bali, 2007), COP15 (Copenhagen, 2009), COP16 (Cancun, 2010), COP17 (Durban, 2011), COP18 (Doha, 2012), COP19 (Warsaw, 2013), COP21 and (Paris, 2015).There are other International legal instruments such as 1979 Geneva Convention on Long-Range Trans-boundary Air Pollution. Against this backdrop, this paper will critically examine the existing International legal regime (treaties, conventions, agreements, etc.) on global warming and climate change