scholarly journals Five-brane current algebras in type II string theories

2021 ◽  
Vol 2021 (3) ◽  
Author(s):  
Machiko Hatsuda ◽  
Shin Sasaki ◽  
Masaya Yata

Abstract We study the current algebras of the NS5-branes, the Kaluza-Klein (KK) five-branes and the exotic $$ {5}_2^2 $$ 5 2 2 -branes in type IIA/IIB superstring theories. Their worldvolume theories are governed by the six-dimensional $$ \mathcal{N} $$ N = (2, 0) tensor and the $$ \mathcal{N} $$ N = (1, 1) vector multiplets. We show that the current algebras are determined through the S- and T-dualities. The algebras of the $$ \mathcal{N} $$ N = (2, 0) theories are characterized by the Dirac bracket caused by the self-dual gauge field in the five-brane worldvolumes, while those of the $$ \mathcal{N} $$ N = (1, 1) theories are given by the Poisson bracket. By the use of these algebras, we examine extended spaces in terms of tensor coordinates which are the representation of ten-dimensional supersymmetry. We also examine the transition rules of the currents in the type IIA/IIB supersymmetry algebras in ten dimensions. Based on the algebras, we write down the section conditions in the extended spaces and gauge transformations of the supergravity fields.

2021 ◽  
Vol 81 (3) ◽  
Author(s):  
Yasser Akou ◽  
Mohammad R. Garousi

AbstractThe effective action of string theory has both bulk and boundary terms if the spacetime is an open manifold. Recently, the known classical effective action of string theory at the leading order of $$\alpha '$$ α ′ and its corresponding boundary action have been reproduced by constraining the effective actions to be invariant under gauge transformations and under string duality transformations. In this paper, we use this idea to find the classical effective action of the O-plane and its corresponding boundary terms in type II superstring theories at order $$\alpha '^2$$ α ′ 2 and for NS–NS couplings. We find that these constraints fix the bulk action and its corresponding boundary terms up to one overall factor. They also produce three multiplets in the boundary action that their coefficients are independent of the bulk couplings under the string dualities.


1996 ◽  
Vol 11 (10) ◽  
pp. 827-834 ◽  
Author(s):  
ASHOKE SEN

We investigate possible existence of duality symmetries which exchange the Kaluza–Klein modes with the wrapping modes of a BPS saturated p-brane on a torus. Assuming the validity of the conjectured U-duality symmetries of type-II and heterotic string theories and M-theory, we show that for a BPS saturated p-brane there is an SL (2, Z) symmetry that mixes the Kaluza–Klein modes on a (p+1)-dimensional torus T(p+1) with the wrapping modes of the p-brane on T(p+1). The field that transforms as a modular parameter under this SL (2, Z) transformation has as its real part the component of the (p+1)-form gauge field on T(p+1), and as its imaginary part the volume of T(p+1), measured in the metric that couples naturally to the p-brane.


2020 ◽  
Vol 0 (0) ◽  
Author(s):  
Tejinder P. Singh

AbstractWe have recently proposed a Lagrangian in trace dynamics at the Planck scale, for unification of gravitation, Yang–Mills fields, and fermions. Dynamical variables are described by odd-grade (fermionic) and even-grade (bosonic) Grassmann matrices. Evolution takes place in Connes time. At energies much lower than Planck scale, trace dynamics reduces to quantum field theory. In the present paper, we explain that the correct understanding of spin requires us to formulate the theory in 8-D octonionic space. The automorphisms of the octonion algebra, which belong to the smallest exceptional Lie group G2, replace space-time diffeomorphisms and internal gauge transformations, bringing them under a common unified fold. Building on earlier work by other researchers on division algebras, we propose the Lorentz-weak unification at the Planck scale, the symmetry group being the stabiliser group of the quaternions inside the octonions. This is one of the two maximal sub-groups of G2, the other one being SU(3), the element preserver group of octonions. This latter group, coupled with U(1)em, describes the electrocolour symmetry, as shown earlier by Furey. We predict a new massless spin one boson (the ‘Lorentz’ boson) which should be looked for in experiments. Our Lagrangian correctly describes three fermion generations, through three copies of the group G2, embedded in the exceptional Lie group F4. This is the unification group for the four fundamental interactions, and it also happens to be the automorphism group of the exceptional Jordan algebra. Gravitation is shown to be an emergent classical phenomenon. Although at the Planck scale, there is present a quantised version of the Lorentz symmetry, mediated by the Lorentz boson, we argue that at sub-Planck scales, the self-adjoint part of the octonionic trace dynamics bears a relationship with string theory in 11 dimensions.


1996 ◽  
Vol 10 (13n14) ◽  
pp. 1695-1705 ◽  
Author(s):  
S. Ansoldi ◽  
A. Aurilia ◽  
E. Spallucci

We study a functional field theory of membranes coupled to a rank-three tensor gauge potential. We show that gauge field radiative corrections lead to membrane condensation which turns the gauge field into a massive spin-0 field. This is the Coleman-Weinberg mechanism for membranes. An analogy is also drawn with a type-II superconductor. The ground state of the system consists of a two-phase medium in which the superconducting background condensate is “pierced” by four-dimensional domains, or “bags”, of non-superconducting vacuum. Bags are bounded by membranes whose physical thickness is of the order of the inverse mass acquired by the gauge field.


2018 ◽  
Vol 26 (9) ◽  
pp. 667-676
Author(s):  
Yuk Law ◽  
Yiu Che Chan ◽  
Stephen Wing-Keung Cheng

Introduction We performed a single-center nonrandomized study on patients who underwent endovascular aneurysm repair using polymer-filled or other self-expanding endografts. Methods Consecutive patients with asymptomatic infrarenal abdominal aortic aneurysms who underwent endovascular repair were retrospectively reviewed. They were divided into a polymer-filled ( n = 20) or self-expanding group ( n = 42). Baseline characteristics, operative mortality and morbidity, and follow-up data were compared. Results Aneurysm diameter, neck and iliac morphologies did not differ between the two groups. Technical success was 100%. The 30-day mortality was 0% and 2.4% in the polymer-filled and self-expanding group, respectively. At a mean follow-up of 17 months, the changes in sac size were −2.1 mm and −5.1 mm ( p = 0.144) at one year, and −3.5 mm and −7.7 mm ( p = 0.287) at 2 years in the polymer-filled and self-expanding group, respectively. The polymer-filled group had 7 (35%) type II endoleaks, and the self-expanding group had 1 (2.4%) type Ia and 13 (31%) type II endoleaks. Neck diameter remained stable in the polymer-filled stent-grafts whereas there was progressive neck degeneration in the self-expanding group. The rates of reintervention and overall survival were similar in both groups. The presence of an endoleak was the only predictor of non-regression of the aneurysm (odds ratio = 17.00, 95% confidence interval: 4.46–64.88, p < 0.001). Conclusion Polymer-filled endografts had similar safety, effectiveness, and durability to other self-expanding endografts. The major advantage is the small iliofemoral access. They also have the potential long-term benefit of a more stable neck.


1988 ◽  
Vol 03 (14) ◽  
pp. 1379-1384
Author(s):  
N.V. KRASNIKOV

We give an example of the grand unified model without monopoles which arises in Kaluza-Klein compactification of a pure gauge field theory of the special kind.


2008 ◽  
Vol 23 (30) ◽  
pp. 4841-4859 ◽  
Author(s):  
EUGEN-MIHĂIŢĂ CIOROIANU ◽  
EUGEN DIACONU ◽  
SILVIU CONSTANTIN SĂRARU

The interactions that can be introduced between a massless Rarita–Schwinger field and an Abelian three-form gauge field in 11 space–time dimensions are analyzed in the context of the deformation of the "free" solution of the master equation combined with local BRST cohomology. Under the hypotheses of smoothness of the interactions in the coupling constant, locality, Poincaré invariance, Lorentz covariance, and the presence of at most two derivatives in the Lagrangian of the interacting theory (the same number of derivatives as in the free Lagrangian), we prove that there are neither cross-couplings nor self-interactions for the gravitino in D = 11. The only possible term that can be added to the deformed solution to the master equation is nothing but a generalized Chern–Simons term for the three-form gauge field, which brings contributions to the deformed Lagrangian, but does not modify the original, Abelian gauge transformations.


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