U(1) gauge invariance from open string field theory

The naive low energy effective action of the tachyon and the U(1) gauge field obtained from string field theory does not correspond to the world volume action of unstable branes in bosonic string theory. We show that there exists a field redefinition which relates the gauge field and the tachyon of the string field theory action to the fields in the world volume action of unstable branes. We identify a string gauge symmetry which corresponds to the U(1) gauge transformation. This is done to the first non-linear order in the fields. We examine the vector fluctuations at the tachyon condensate till level (4,8).Comment: Section on transverse photon at tachyon condensate added, 23 pages, Uses JHEP.cl

Phase Separation, Competition, and Volume Fraction Control in NaFe1−x_{1-x}Cox_xAs

We report a detailed nuclear magnetic resonance (NMR) study by combined $^{23}$Na and $^{75}$As measurements over a broad range of doping to map the phase diagram of NaFe$_{1-x}$Co$_x$As. In the underdoped regime ($x \le$ 0.017), we find a magnetic phase with robust antiferromagnetic (AFM) order, which we denote the {\it s}-AFM phase, cohabiting with a phase of weak and possibly proximity-induced AFM order ({\it w}-AFM) whose volume fraction $V \simeq 8$\% is approximately constant. Near optimal doping, at $x = 0.0175$, we observe a phase separation between static antiferromagnetism related to the {\it s}-AFM phase and a paramagnetic (PM) phase related to {\it w}-AFM. The volume fraction of AFM phase increases upon cooling, but both the N{\'e}el temperature and the volume fraction can be suppressed systematically by applying a $c$-axis magnetic field. On cooling below $T_c$, superconductivity occupies the PM region and its volume fraction grows at the expense of the AFM phase, demonstrating a phase separation of the two types of order based on volume exclusion. At higher dopings, static antiferromagnetism and even critical AFM fluctuations are completely suppressed by superconductivity. Thus the phase diagram we establish contains two distinct types of phase separation and reflects a strong competition between AFM and superconducting phases both in real space and in momentum space. We suggest that both this strict mutual exclusion and the robustness of superconductivity against magnetism are consequences of the extreme two-dimensionality of NaFeAs.Comment: 12 pages, 6 figure

Finite volume corrections to the binding energy of the X(3872)

The quark mass dependence of hadrons is an important input for lattice calculations. We investigate the light quark mass dependence of the binding energy of the X(3872) in a finite box to next-to-leading order in an effective field theory for the X(3872) with perturbative pions (XEFT). At this order, the quark mass dependence is determined by a quark mass-dependent contact interaction in addition to the one-pion exchange. While there is only a moderate sensitivity to the light quark masses in the region up to twice their physical value, the finite volume effects are significant already at box length as large as 20 fm.Comment: 23 pages, 9 figures, REVTe

Towards High-order Methods for Rotorcraft Applications

This work presents CFD results obtained with an efficient, high-order, finite-volume scheme. The formulation is based on the variable extrapolation MUSCL-scheme, and high-order spatial accuracy is achieved using correction terms obtained through successive differentiation. The scheme is modified to cope with physical and multiblock mesh interfaces, so stability, conservativeness, and high-order accuracy are guaranteed. Results with the proposed scheme for steady flows, showed better wake and higher resolution of vortical structures compared with the standard MUSCL, even when coarser meshes were employed. The method was also demonstrated for unsteady flows using overset and moving grids for the UH-60A rotor in forward flight and the ERICA tiltrotor in aeroplane mode. The present method adds CPU and memory overheads of 47% and 23%, respectively, in performing multi-dimensional problems for routine computations

Perturbative dynamics of matrix string for the membrane

Recently Sekino and Yoneya proposed a way to regularize the world volume theory of membranes wrapped around $S^1$ by matrices and showed that one obtains matrix string theory as a regularization of such a theory. We show that this correspondence between matrix string theory and wrapped membranes can be obtained by using the usual M(atrix) theory techniques. Using this correspondence, we construct the super-Poincare generators of matrix string theory at the leading order in the perturbation theory. It is shown that these generators satisfy 10 dimensional super-Poincar\'e algebra without any anomaly.Comment: 23 pages, 1 figur

Finite-volume corrections to the leading-order hadronic contribution to gμ−2g_\mu-2

We present preliminary results of a 2+1-flavor study of finite-volume effects in the lattice QCD computation of the leading-order hadronic contribution to the muon anomalous magnetic moment. We also present methods for obtaining directly the invariant hadronic polarization function, $\Pi(Q^2)$, and the Adler function at all discrete lattice values of $Q^2$, including $Q^2=0$. Results are obtained with HEX-smeared clover fermions.Comment: 7 pages, 2 figures, Contribution to the Proceedings of the 32nd International Symposium on Lattice Field Theory (Lattice 2014), 23-28 June 2014, Columbia University, New York, NY, US

Environmental & architectural phenomenology. Cumulative Index (Volumes 1-30, 1990-2019)

This index includes all EAP entries except reference items listed in “citations received.” Entries have been identified in the following order: volume number, issue number, and page(s). Thus 3,2:10, for example, refers to volume 3, issue 2, page 10. Volume numbers by years are as follows: vol. 1—1990; vol. 2—1991; vol. 3—1992; vol. 4—1993; vol. 5—1994; vol. 6—1995; vol. 7—1996; vol. 8—1997; vol. 9—1998; vol. 10—1999; vol. 11—2000; vol. 12—2001; vol. 13—2002; vol. 14—2003; vol. 15—2004; vol. 16—2005; vol. 17—2006; vol. 18—2007; vol. 19—2008; vol. 20—2009; vol. 21—2010; vol. 22—2011; vol. 23—2012; vol. 24—2013; vol. 25—2014; vol. 26—2015; vol. 27—2016; vol. 28—2017; vol. 29—2018; vol. 30—2019. The index categories are: feature essays; thematic issues, book and film reviews; book notes; bibliographies; course outlines; poetry; noteworthy readings; graduate theses; web sites; news from readers; conferences; organizations; refereed journals; book series; other publications; obituaries; topics