Josephson (001) tilt grain boundary junctions of high temperature superconductors

We calculate the critical current $I_c$ across in-plane (001) tilt grain boundary junctions of high temperature superconductors. We solve for the electronic states corresponding to the electron-doped cuprates, two slightly different hole-doped cuprates, and an extremely underdoped hole-doped cuprate in each half-space, and weakly connect the two half-spaces by either specular or random quasiparticle tunneling. We treat symmetric, straight, and fully asymmetric junctions with s-, extended-s-, or d$_{x^2-y^2}$-wave order parameters. For symmetric junctions with random grain boundary tunneling, our results are generally in agreement with the Sigrist-Rice form for ideal junctions that has been used to interpret ``phase-sensitive'' experiments consisting of such in-plane grain boundary junctions. For specular grain boundary tunneling across symmetric juncitons, our results depend upon the Fermi surface topology, but are usually rather consistent with the random facet model of Tsuei {\it et al.} [Phys. Rev. Lett. {\bf 73}, 593 (1994)]. Our results for asymmetric junctions of electron-doped cuparates are in agreement with the Sigrist-Rice form. However, ou resutls for asymmetric junctions of hole-doped cuprates show that the details of the Fermi surface topology and of the tunneling processes are both very important, so that the ``phase-sensitive'' experiments based upon the in-plane Josephson junctions are less definitive than has generally been thought.Comment: 13 pages, 10 figures, resubmitted to PR

Holographic Thermal Helicity

We study the thermal helicity, defined in arXiv:1211.3850, of a conformal field theory with anomalies in the context of AdS$_{2n+1}$/CFT$_{2n}$. To do so, we consider large charged rotating AdS black holes in the Einstein-Maxwell-Chern-Simons theory with a negative cosmological constant using fluid/gravity expansion. We compute the anomaly-induced current and stress tensor of the dual CFT in leading order of the fluid/gravity derivative expansion and show their agreement with the field theoretical replacement rule for the thermal helicity. Such replacement rule is reflected in the bulk by new replacement rules obeyed by the Hall currents around the black hole.Comment: 20 pages + 47 pages of appendices ; v2: minor correction

Covariant Noether Charge for Higher Dimensional Chern-Simons Terms

We construct a manifestly covariant differential Noether charge for theories with Chern-Simons terms in higher dimensional spacetimes. This is in contrast to Tachikawa's extension of the standard Lee-Iyer-Wald formalism which results in a non-covariant differential Noether charge for Chern-Simons terms. On a bifurcation surface, our differential Noether charge integrates to the Wald-like entropy formula proposed by Tachikawa in arXiv:hep-th/0611141.Comment: 45 pages; v2: minor corrections and JHEP versio

Analisis Ketahanan Pangan Provinsi Sumatera Utara dengan Metode Regresi Data Panel

Krisis pangan sedang mengancam Indonesia. Berbagai tanggapanmengutarakan kondisi ini terjadi karena kemampuan untuk memproduksi beras se-makin menurun sementara jumlah konsumsi beras semakin bertambah seiring den-gan bertambahnya jumlah penduduk. Sumatera Utara yang terdiri dari 33 kabu-paten/ kota saat ini memiliki kondisi dan karakteristik pangan beras yang berbedamisalnya kondisi stok beras, luas areal panen padi, produktivitas lahan, jumlahkonsumsi beras dan harga beras. Oleh karena itu penelitian ini bertujuan untukmenganalisis ketahanan pangan Provinsi Sumatera Utara yang diukurmenggunakankondisi-kondisi tersebut dengan rasio ketersediaan beras sebagai proxyketahananpangan. Metode analisis yang digunakan adalah metode regresi data panel. Regresidata panel adalah regresi yang diperoleh dari gabungan data cross section dan datatime seriessehingga diperoleh data yang lebih besar dan dapat menigkatkan presisidari model regresi yang diperoleh. Hasil penelitian menunjukkan bahwa variabelluas areal panen padi dan produktivitas lahan berpengaruh positif dan signifikanterhadap rasio ketersediaan beras. Jumlah konsumsi beras berpengaruh negatif dansignifikan, sedangkan stok beras berpengaruh positif namun tidak signifikan, danharga beras berpengaruh negatif namun tidak signifikan terhadap rasio ketersediaanberas di Sumatera Utara

Earnings and wealth inequality and income taxation: quantifying the tradeoffs of switching to a proportional income tax in the U.S.

This paper quantifies the steady-state aggregate, distributional, and mobility effects of switching the U.S. to a proportional income tax system.Income tax

Blue Straggler Stars in Galactic Open Clusters and the effect of field star contamination

We investigate the distribution of Blue Straggler stars in the field of three open star clusters. The main purpose is to highlight the crucial role played by general Galactic disk fore-/back-ground field stars, which are often located in the same region of the Color Magnitude Diagram as Blue Straggler stars. We analyze photometry taken from the literature of 3 open clusters of intermediate/old age rich in Blue Straggler stars, and which are projected in the direction of the Perseus arm, and study their spatial distribution and the Color Magnitude Diagram. As expected, we find that a large portion of the Blue Straggler population in these clusters are simply young field stars belonging to the spiral arm. This result has important consequences on the theories of the formation and statistics of Blue Straggler stars in different population environments: open clusters, globular clusters or dwarf galaxies. As previously emphasized by many authors, a detailed membership analysis is mandatory before comparing the Blue Straggler population in star clusters against theoretical models. Moreover, these sequences of young field stars (blue plumes) are potentially powerful tracers of Galactic structure which require further consideration.Comment: 11 pages, 4 figurs, in press as Research Note in A&

3DFeat-Net: Weakly Supervised Local 3D Features for Point Cloud Registration

In this paper, we propose the 3DFeat-Net which learns both 3D feature detector and descriptor for point cloud matching using weak supervision. Unlike many existing works, we do not require manual annotation of matching point clusters. Instead, we leverage on alignment and attention mechanisms to learn feature correspondences from GPS/INS tagged 3D point clouds without explicitly specifying them. We create training and benchmark outdoor Lidar datasets, and experiments show that 3DFeat-Net obtains state-of-the-art performance on these gravity-aligned datasets.Comment: 17 pages, 6 figures. Accepted in ECCV 201