The orbifold cohomology of moduli of hyperelliptic curves

We study the inertia stack of [M_{0,n}/S_n], the quotient stack of the moduli space of smooth genus 0 curves with n marked points via the action of the symmetric group S_n. Then we see how from this analysis we can obtain a description of the inertia stack of H_g, the moduli stack of hyperelliptic curves of genus g. From this, we can compute additively the Chen-Ruan (or orbifold) cohomology of H_g.Comment: 15 pages. We correct an error in Proposition 3.3 of the published paper, and its consequence

Twisted K-Theory for the Orbifold [*/G]

We study the relationship between the twisted Orbifold K-theories {^{\alpha}}K_{orb}(\textsl{X}) and {^{\alpha'}}K_{orb}(\textsl{Y}) for two different twists $\alpha\in Z^3(G;S^1)$ and $\alpha'\in Z^3(G';S^1)$ of the Orbifolds \textsl{X}=[*/G] and \textsl{Y}=[*/G'] respectively, for $G$ and $G'$ finite groups. We prove that under suitable hypothesis over the twisting $\alpha'$ and the group $G'$ we obtain an isomorphism between these twisted K-theories.Comment: version accepted in Pacific Journal of Mathematic

Recital: Ensemble for Pianists, December 8, 2016

This is the concert program of the Recital: Ensemble for Pianists on Thursday, December 8, 2016 at 6:00 p.m., at the Concert Hall, 855 Commonwealth Avenue. Works performed were Variations on a Theme by Paganini by Witold Lutoslawski, I. Prologue; "Extremement lent et calme" from Sonata by Francis Poulenc, III. Scherzo: "Allegro molto" from Sonata in F minor, Opus 34b by Johannes Brahms, I. Old Adam from The Garden of Eden by William Bolcom, IV. Epilogue; "Allegro giocoso" by F. Poulenc, Fantasy in A minor, Opus posth. by Alexander Scriabin, III. Tears in G minor from Suite no 1, Opus 5 ("Fantasie-Tableaux") by Sergei Rachmaninoff, Dance Macabre, OPus 40 by Camille Saint-Saëns, Rondo in C major, Opus 73 by Frédéric Chopin, III. The Serpent's Kiss from The Garden of Eden by W. Bolcom, and IV. Tarantella in G minor from Suite no 2, Opus 17 by S. Rachmaninoff. Digitization for Boston University Concert Programs was supported by the Boston University Humanities Library Endowed Fund

A slot-loaded reduced-size CPW-fed aperture antenna for UWB applications

The paper presents a co-planar wave guide (CPW)-fed slot loaded low return loss planar printed antenna with a small size designed for wireless communication and UWB applications. First, a conventional UWB antenna is modeled to provide a reference point for the modeling and then the shape is modified by a self inverted configuration to achieve higher bandwidth and size reduction. To improve the gain and efficiency, a combination of corner features and loading slots are introduced. The primary aim throughout the modeling was to achieve the minimum possible value of return loss (S11) below -10 dB over the FCC-defined UWB frequency range. The antenna was designed, simulated and modified using Agilent's Advanced Design System (ADS). It was fabricated on FR4 substrate and measured return loss results are presented

Higgs measurement at e+e- circular colliders

Now that the mass of the Higgs boson is known, circular electron positron colliders, able to measure the properties of these particles with high accuracy, are receiving considerable attention. Design studies have been launched (i) at CERN with the Future Circular Colliders (FCC), of which an e+e- collider is a potential first step (FCC-ee, formerly caller TLEP) and (ii) in China with the Circular Electron Positron Collider (CEPC). Hosted in a tunnel of at least 50 km (CEPC) or 80-100 km (FCC), both projects can deliver very high luminosity from the Z peak to HZ threshold (CEPC) and even to the top pair threshold and above (FCC-ee). At the ZH production optimum, around 240 GeV, the FCC-ee (CEPC) will be able to deliver 10 (5) ab-1 integrated luminosity in 5 (10) years with 4 (2) interaction points: hence to produce millions of Higgs bosons through the Higgsstrahlung process and vector boson fusion processes. This sample opens the possibility of subper- cent precision absolute measurements of the Higgs boson couplings to fermions and to gauge-bosons, and of the Higgs boson width. These precision measurements are potentially sensitive to multi-TeV range new physics interacting with the scalar sector. The ZH production mechanism also gives access to the invisible or exotic branching ratios down to the per mil level, and with a more limited precision to the triple Higgs coupling. For the FCC-ee, the luminosity expected at the top pair production threshold (sqrt(s) ~ 340-350 GeV) further improves some of these accuracies significantly, and is sensitive to the Higgs boson coupling to the top quark.Comment: 6 pages. Report at ICHEP 201

Orbifold Singularities of Hitchin fibres: the case (SLn,PGLn)(\text{SL}_n,\text{PGL}_n)

We prove a conjecture of Frenkel and Witten concerning the singularities of Hitchin fibres in the case of dual Hitchin systems ($\mathcal{M}_C(\text{SL}_n),\mathcal{M}_C(\text{PGL}_n)$) for a connected smooth projective complex curve $C$ with genus $g>1$