Open String Amplitudes in Various Gauges

Recently, Schnabl constructed the analytic solution of the open string tachyon. Subsequently, the absence of the physical states at the vacuum was proved. The development relies heavily on the use of the gauge condition different from the ordinary one. It was shown that the choice of gauge simplifies the analysis drastically. When we perform the calculation of the amplitudes in Schnabl gauge, we find that the off-shell amplitudes of the Schnabl gauge is still very complicated. In this paper, we propose the use of the propagator in the modified Schnabl gauge and show that this modified use of the Schnabl gauge simplifies the computation of the off-shell amplitudes drastically. We also compute the amplitudes of open superstring in this gauge.Comment: 23 pages, minor correction

Tipologi Apartemen di Sekitar Fasilitas Pendidikan Kota Bandung dan Jatinangor

TIPOLOGI APARTEMEN DI SEKITAR FASILITAS PENDIDIKAN KOTA BANDUNG DAN JATINANGOR Erisa Weri Nydia, Panji Nusantara Sakti, Eva Nurjanah, Fuji Ratna Mustika Jurusan Teknik Arsitektur, Fakultas Teknik Sipil dan Perencanaan Institut Teknologi Nasional Email: [email protected] ABSTRAK Pembangunan hunian bagi pelajar atau mahasiswa berkembang pesat di sekitar fasilitas pendidikan terutama di kota-kota besar, hal ini menyebabkan keterbatasan lahan hunian tidak sebanding dengan jumlah pendatang, sehingga sasaran baru sektor properti pengembang adalah membangun apartemen sebagai alternatif hunian vertikal kota di sekitar fasilitas pendidikan. Kajian ini bertujuan untuk mengetahui tipologi yang terdapat pada beberapa apartemen yang berlokasi di sekitar fasilitas pendidikan di Kota Bandung dan Jatinangor. Lingkup studi pada kajian ini meliputi dua aspek, yaitu dari aspek arsitektural dan non-arsitektural. Aspek arsitektural membahas tipologi mengenai block plan, denah, unit, fasad, massa bangunan, dan fasilitas umum. Sedangkan dari aspek non-arsitektural membahas mengenai karakteristik penghuni. Metode analisis yang digunakan adalah induktif terhadap tipologi dimana data diklasifikasikan berdasarkan kesamaan karakteristik. Hasil yang didapat adalah terdapat beberapa persamaan dari keempat apartemen yang berlokasi di sekitar fasilitas pendidikan. Ditinjau dari komposisi unitnya, perbandingan komposisi unit studio apartemen yang berlokasi di sekitar fasilitas pendidikan lebih besar dibandingkan apartemen umum. Adapun beberapa fasilitas umum yang sering ditemukan di dalam apartemen yang berlokasi di sekitar fasilitas pendidikan yaitu, kolam renang, minimart, gym, laundry, dan taman. Kata kunci : apartemen, fasilitas pendidikan, tipologi ABSTRACT Residential development for students is growing rapidly around educational facilities, especially in big cities, this has led to limited land occupancy which is not proportional to the number of entrants, it becomes the new target for real estate developers to build apartments as an alternative to residential vertical city around educational facilities. This study aims to determine the typology in some of the apartments which are located around educational facilities in Bandung and Jatinangor. The scope of the study in this research includes two aspects, from the architectural aspects and non-architectural aspects. Architectural aspects discusses the typology of the block plan, floor plans, units, facades, building mass, and public facilities. Meanwhile, from the non-architectural aspect discuss the characteristics of the occupants. The analytical method used is inductive to the typology where data is classified based on similar characteristics. The result is that there is some similarities of the four apartments that is located around educational facilities. Based on composition of the unit, unit composition ratio studio apartment that is located around educational facilities is greater than common apartment. The number of public facilities that are often found inside apartments, such as swimming pool, minimart, gym, laundry, and park. ­

On Exact Superpotentials, Free Energies and Matrix Models

We discuss exact results for the full nonperturbative effective superpotentials of four dimensional $\mathcal{N}=1$ supersymmetric U(N) gauge theories with additional chiral superfield in the adjoint representation and the free energies of the related zero dimensional bosonic matrix models with polynomial potentials in the planar limit using the Dijkgraaf-Vafa matrix model prescription and integrating in and out. The exact effective superpotentials are produced including the leading Veneziano-Yankielowicz term directly from the matrix models. We also discuss how to use integrating in and out as a tool to do random matrix integrals in the large $N$ limit.Comment: 14 pages; v2: typos corrected; v3: the scheme for computing exact superpotentials including both the Veneziano-Yankielowicz term and all instanton corrections directly using matrix models is emphasized and references added, to appear in JHE

Chiral Rings and Anomalies in Supersymmetric Gauge Theory

Motivated by recent work of Dijkgraaf and Vafa, we study anomalies and the chiral ring structure in a supersymmetric U(N) gauge theory with an adjoint chiral superfield and an arbitrary superpotential. A certain generalization of the Konishi anomaly leads to an equation which is identical to the loop equation of a bosonic matrix model. This allows us to solve for the expectation values of the chiral operators as functions of a finite number of ``integration constants.'' From this, we can derive the Dijkgraaf-Vafa relation of the effective superpotential to a matrix model. Some of our results are applicable to more general theories. For example, we determine the classical relations and quantum deformations of the chiral ring of $\N=1$ super Yang-Mills theory with SU(N) gauge group, showing, as one consequence, that all supersymmetric vacua of this theory have a nonzero chiral condensate.Comment: 67 pages, minor change

Fivebranes and 4-manifolds

We describe rules for building 2d theories labeled by 4-manifolds. Using the proposed dictionary between building blocks of 4-manifolds and 2d N=(0,2) theories, we obtain a number of results, which include new 3d N=2 theories T[M_3] associated with rational homology spheres and new results for Vafa-Witten partition functions on 4-manifolds. In particular, we point out that the gluing measure for the latter is precisely the superconformal index of 2d (0,2) vector multiplet and relate the basic building blocks with coset branching functions. We also offer a new look at the fusion of defect lines / walls, and a physical interpretation of the 4d and 3d Kirby calculus as dualities of 2d N=(0,2) theories and 3d N=2 theories, respectivelyComment: 81 pages, 18 figures. v2: misprints corrected, clarifications and references added. v3: additions and corrections about lens space theory, 4-manifold gluing, smooth structure

Semiclassical Strings Probing NS5 Brane Wrapped on S^5

We study little string theory on R^1 x S^5, defined by a theory which lives on type IIA N NS5 branes wrapped on S^5, using its supergravity dual. In particular we study semiclassical rotating closed strings in this background. We also consider Penrose limit of this background that leads to a plane wave on which string theory is exactly solvable.Comment: 14 pages, Latex, v2: typos corrected, Refs. added, v3: typos correcte

Penrose Limit and String Theories on Various Brane Backgrounds

We investigate the Penrose limit of various brane solutions including Dp-branes, NS5-branes, fundamental strings, (p,q) fivebranes and (p,q) strings. We obtain special null geodesics with the fixed radial coordinate (critical radius), along which the Penrose limit gives string theories with constant mass. We also study string theories with time-dependent mass, which arise from the Penrose limit of the brane backgrounds. We examine equations of motion of the strings in the asymptotic flat region and around the critical radius. In particular, for (p,q) fivebranes, we find that the string equations of motion in the directions with the B field are explicitly solved by the spheroidal wave functions.Comment: 41 pages, Latex, minor correction

More on Penrose limits and non-local theories

We obtain the Penrose limit of six dimensional Non-Commutative Open String (NCOS$_6$) theory and show that in the neighborhood of a particular null geodesic it leads to an exactly solvable string theory (unlike their counterparts in four or in other dimensions). We describe the phase structure of this theory and discuss the Penrose limit in different phases including Open D-string (OD1) theory. We compute the string spectrum and discuss their relations with the states of various theories at different phases. We also consider the case of general null geodesic for which the Penrose limit leads to string theory in the time dependent pp-wave background and comment on the renormalization group flow in the dual theory.Comment: latex, 22 pages, minor corrections, references added, published versio

Marginal deformations in string field theory

We describe a method for obtaining analytic solutions corresponding to exact marginal deformations in open bosonic string field theory. For the photon marginal deformation we have an explicit analytic solution to all orders. Our construction is based on a pure gauge solution where the gauge field is not in the Hilbert space. We show that the solution itself is nevertheless perfectly regular. We study its gauge transformations and calculate some coefficients explicitly. Finally, we discuss how our method can be implemented for other marginal deformations.Comment: 23 pages. v2: Some paragraphs improved, typos corrected, ref adde

Exact Superpotentials, Theories with Flavor and Confining Vacua

In this paper we study some interesting properties of the effective superpotential of N=1 supersymmetric gauge theories with fundamental matter, with the help of the Dijkgraaf--Vafa proposal connecting supersymmetric gauge theories with matrix models. We find that the effective superpotential for theories with N_f fundamental flavors can be calculated in terms of quantities computed in the pure (N_f=0) gauge theory. Using this property we compute in a remarkably simple way the exact effective superpotential of N=1 supersymmetric theories with fundamental matter and gauge group SU(N_c), at the point in the moduli space where a maximal number of monopoles become massless (confining vacua). We extend the analysis to a generic point of the moduli space, and show how to compute the effective superpotential in this general case.Comment: 16 pages, no figure