Aspects of AdS/BCFT

We expand the results of arXiv:1105.5165, where a holographic description of a conformal field theory defined on a manifold with boundaries (so called BCFT) was proposed, based on AdS/CFT. We construct gravity duals of conformal field theories on strips, balls and also time-dependent boundaries. We show a holographic g-theorem in any dimension. As a special example, we can define a `boundary central charge' in three dimensional conformal field theories and our holographic g-theorem argues that it decreases under RG flows. We also computed holographic one-point functions and confirmed that their scaling property agrees with field theory calculations. Finally, we give an example of string theory embedding of this holography by inserting orientifold 8-planes in AdS(4)xCP(3).Comment: 41 pages, 10 figures; v2: further comments on earlier papers about a holographic dual with boundarie

Managing variety to establish viable videoconferencing in remote music tuition from an educational technologist's viewpoint

https://www.ester.ee/record=b5163152*es

Holographic entanglement entropy: near horizon geometry and disconnected regions

We study the finite term of the holographic entanglement entropy for the charged black hole in AdS(d+2) and other examples of black holes when the spatial region in the boundary theory is given by one or two parallel strips. For one large strip it scales like the width of the strip. The divergent term of its expansion as the turning point of the minimal surface approaches the horizon is determined by the near horizon geometry. Examples involving a Lifshitz scaling are also considered. For two equal strips in the boundary we study the transition of the mutual information given by the holographic prescription. In the case of the charged black hole, when the width of the strips becomes large this transition provides a characteristic finite distance depending on the temperature

Florentino Ameghino : Un siglo de estratigrafía pampeana

Fil: Tonni, Eduardo Pedro. División Paleontología Vertebrados. Facultad de Ciencias Naturales y Museo. Universidad Nacional de La Plata; Argentin

Entanglement negativity in quantum field theory

We develop a systematic method to extract the negativity in the ground state of a 1+1 dimensional relativistic quantum field theory, using a path integral formalism to construct the partial transpose rho_A^{T_2} of the reduced density matrix of a subsystem A=A1 U A2, and introducing a replica approach to obtain its trace norm which gives the logarithmic negativity E=ln||\rho_A^{T_2}||. This is shown to reproduce standard results for a pure state. We then apply this method to conformal field theories, deriving the result E\sim(c/4) ln(L1 L2/(L1+L2)) for the case of two adjacent intervals of lengths L1, L2 in an infinite system, where c is the central charge. For two disjoint intervals it depends only on the harmonic ratio of the four end points and so is manifestly scale invariant. We check our findings against exact numerical results in the harmonic chain.Comment: 4 pages, 5 figure

Modular Hamiltonians for the massless Dirac field in the presence of a boundary

We study the modular Hamiltonians of an interval for the massless Dirac fermion on the half-line. The most general boundary conditions ensuring the global energy conservation lead to consider two phases, where either the vector or the axial symmetry is preserved. In these two phases we derive the corresponding modular Hamiltonian in explicit form. Its density involves a bi-local term localised in two points of the interval, one conjugate to the other. The associated modular flows are also established. Depending on the phase, they mix fields with different chirality or charge that follow different modular trajectories. Accordingly, the modular flow preserves either the vector or the axial symmetry. We compute the two-point correlation functions along the modular flow and show that they satisfy the Kubo-Martin-Schwinger condition in both phases. The entanglement entropies are also derived

Modular Hamiltonians for the massless Dirac field in the presence of a defect

We study the massless Dirac field on the line in the presence of a point-like defect characterised by a unitary scattering matrix, that allows both reflection and transmission. Considering this system in its ground state, we derive the modular Hamiltonians of the subregion given by the union of two disjoint equal intervals at the same distance from the defect. The absence of energy dissipation at the defect implies the existence of two phases, where either the vector or the axial symmetry is preserved. Besides a local term, the densities of the modular Hamiltonians contain also a sum of scattering dependent bi-local terms, which involve two conjugate points generated by the reflection and the transmission. The modular flows of each component of the Dirac field mix the trajectory passing through a given initial point with the ones passing through its reflected and transmitted conjugate points. We derive the two-point correlation functions along the modular flows in both phases and show that they satisfy the Kubo-Martin-Schwinger condition. The entanglement entropies are also computed, finding that they do not depend on the scattering matrix

Aplikasi Pembelajaran Apotik Hidup Obat Tradisional

Development of life pharmacy learning for the community. This online learning system aims to provide information on natural medicines and types of plants as well as the functions of each plant to the community, which are made online. Based on the above problem formulation, the purpose of this study is to build a web-based life pharmacy learning system that can be used as a facility to inform medicinal plants used for treatment in the community which is inherited by ancestors. With this computer-based life pharmacy learning it can help everyone who wants to learn about what plants can be processed into traditional medicines that are good and healthy and also the function and use of these drugs

RANCANG BANGUN APLIKASI GAME EDUKASI PAKAIAN ADAT BATAK BERBASIS ANDROID

Kurangnya media pendukung yang tepat dalam pengenalan Pakaian Adat Batak membuat generasi muda sekarang kurang mengenal pakaian adat Batak. Untuk itu diperlukan sebuah media yang tepat dalam pengenalan pakaian adat Batak, salah satunya melalui game edukasi yang menarik dan dapat memberikan informasi mengenai Pakaian Adat Batak dengan cara yang berbeda. Salah satu game edukasi yang banyak dibuat adalah Game Puzzle. Game puzzle sangat cocok untuk pembuatan aplikasi ini karena game puzzle mengandung sebuah teknik pemecahan teka-teki. Dengan menggunakan aplikasi ini diharapkan masyarakat dapat lebih memperdulikan pengetahuan tentang pakaian adat Batak. Dalam pembuatan Game ini Penulis menggunakan metodologi Waterfall. Aplikasi Game Edukasi Pakaian Adat Batak menjadi sarana untuk permainan dan pembelajaran kepada Masyarakat luas khususnya bagi suku Batak dengan cara yang mudah dan menarik