On expansions in neutrino effective field theory

We match the seesaw model for generating neutrino masses onto the Standard Model Effective Field Theory (SMEFT). We perform this matching at tree level up to dimension seven in the operator expansion. We explain how some of the perturbations of the neutrino mass matrix due to operators of mass dimension greater than five are tied to integrating out the heavy Majorana mass eigenstates in sequence. We demonstrate that the low energy limit of seesaw models are well described by the SMEFT, particularly when constructed using a flavour space expansion. Flavour space expansions of seesaw models are of interest as the coupling of the heavy states to the Standard Model, that are integrated out to generate neutrino masses, are through flavour space vectors $\in \mathbb{C}^3$. We point out that neutrino phenomenology can be systematically developed as a perturbation around the unknown eigenvectors diagonalizing the charged lepton mass matrix using the fact that these eigenvectors also form a basis of $\mathbb{C}^3$. This point holds in seesaw models and can also be applied to other models of neutrino mass generation to develop systematic expansions. We develop the algebra for this flavour space and discuss some phenomenology to illustrate this approach.Comment: 16 pages + appendix, 3 figures, one nice algebra, V3: minor correction

Situating Climate Security, The Department of Defense's Role in Mitigating Climate Change's Causes and Dealing with its Effects; Strategic Insights; v. 9, issue 2 (Fall 2010) pp. 13-25.

This article appeared in Strategic Insights, v.9, issue 2 (Fall 2010) pp. 13-25.An Emerging Security Focus: Climate Security. A new concern is circulating among policymakers, think tanks, and scholars: securing the planet’s climate. For those who debate what counts as “national security,” the question over whether climate change should be framed as a security issue has been argued along well-worn lines. For those who seek a more expansive definition of security, one that reaches beyond military threats, the threat of climate change is another reason why the lines of security need to be re-drawn. For those who see the inclusion of climate change as a threat to the notion of security as the protection of the state in a competitive international system, widening the term to encompass climate change threatens to draw attention away from traditional threats (future peer competitors like China and a resurgent Russia) and the “new nontraditional” threats (rogue states and transnational terrorism). At the most basic level, the inclusion of environmental threats in a security paradigm risks confusing national security with foreign policy and global politics. As this article will show, however, in many ways this debate has already become obsolete. Since the issuance of the 2007 Intergovernmental Panel on Climate Change (IPCC) estimates, the publication of a bevy of key reports by respected think tanks, and most recently the latest Defense Department Quadrennial Defense Review (QDR) and the National Security Strategy (NSS), climate security has increasingly become recognized as a legitimate object of national security thinking.Approved for public release; distribution is unlimited

Corruption and democracy in Brazil

Interview with Dr. Timothy Power, Professor at Oxford University about the recent chalenges of democracy in Brazil, especially regarding corruption

Linking Sheet Music and Audio - Challenges and New Approaches

Score and audio files are the two most important ways to represent, convey, record, store, and experience music. While score describes a piece of music on an abstract level using symbols such as notes, keys, and measures, audio files allow for reproducing a specific acoustic realization of the piece. Each of these representations reflects different facets of music yielding insights into aspects ranging from structural elements (e.g., motives, themes, musical form) to specific performance aspects (e.g., artistic shaping, sound). Therefore, the simultaneous access to score and audio representations is of great importance. In this paper, we address the problem of automatically generating musically relevant linking structures between the various data sources that are available for a given piece of music. In particular, we discuss the task of sheet music-audio synchronization with the aim to link regions in images of scanned scores to musically corresponding sections in an audio recording of the same piece. Such linking structures form the basis for novel interfaces that allow users to access and explore multimodal sources of music within a single framework. As our main contributions, we give an overview of the state-of-the-art for this kind of synchronization task, we present some novel approaches, and indicate future research directions. In particular, we address problems that arise in the presence of structural differences and discuss challenges when applying optical music recognition to complex orchestral scores. Finally, potential applications of the synchronization results are presented

Towards Bridging the Gap between Sheet Music and Audio

Sheet music and audio recordings represent and describe music on different semantic levels. Sheet music describes abstract high-level parameters such as notes, keys, measures, or repeats in a visual form. Because of its explicitness and compactness, most musicologists discuss and analyze the meaning of music on the basis of sheet music. On the contrary, most people enjoy music by listening to audio recordings, which represent music in an acoustic form. In particular, the nuances and subtleties of musical performances, which are generally not written down in the score, make the music come alive. In this paper, we address the problem of bridging the gap between the sheet music domain and the audio domain. In particular, we discuss aspects on music representations, music synchronization, and optical music recognition, while indicating various strategies and open research problems

Central Binomial Sums, Multiple Clausen Values and Zeta Values

We find and prove relationships between Riemann zeta values and central binomial sums. We also investigate alternating binomial sums (also called Ap\'ery sums). The study of non-alternating sums leads to an investigation of different types of sums which we call multiple Clausen values. The study of alternating sums leads to a tower of experimental results involving polylogarithms in the golden ratio. In the non-alternating case, there is a strong connection to polylogarithms of the sixth root of unity, encountered in the 3-loop Feynman diagrams of {\tt hep-th/9803091} and subsequently in hep-ph/9910223, hep-ph/9910224, cond-mat/9911452 and hep-th/0004010.Comment: 17 pages, LaTeX, with use of amsmath and amssymb packages, to appear in Journal of Experimental Mathematic