We investigate the dynamics of a pair of coincident D5 branes in the background of $k$ NS5 branes. It has been proposed by Kutasov that the system with a single probing D-brane moving radially in this background is dual to the tachyonic DBI action for a non-BPS Dp brane. We extend this proposal to the non-abelian case and find that the duality still holds provided one promotes the radial direction to a matrix valued field associated with a non-abelian geometric tachyon and a particular parametrization for the transverse scalar fields is chosen. The equations of motion of a pair of coincident D5 branes moving in the NS5 background are determined. Analytic and numerical solutions for the pair are found in certain simplified cases in which the U(2) symmetry is broken to $U(1) \times U(1)$ corresponding to a small transverse separation of the pair. For certain range of parameters these solutions describe periodic motion of the centre of mass of the pair 'bouncing off' a finite sized throat whose minimum size is limited by the D5 branes separation.
Tachyon couplings on non-BPS D-branes and Dirac-Born-Infeld action
通过在背景B通量存在下对某些圆盘S-矩阵元的显式计算，我们发现了两个开弦快子与单个非BPS D $p$ -膜的世界体积上的规范场、引力子、介子或Kalb-Ramond反对称张量的耦合.然后，我们提出了一个扩展的阿贝尔狄拉克-玻恩-因菲尔德行动，自然再现这些耦合在场论。这种作用包括快子场的非线性动力学，非常像非BPS D $p$ -膜的其他玻色子模式。在规范变换、T对偶变换和对称迹规定的一般基础上，我们将阿贝尔作用量推广到非阿贝尔情形。
In this short note we perform canonical analysis of geometrical action for Dp-brane. We also discuss tachyon condensation in case of the geometrical action for unstable D(p+1)-brane.
Tachyons on Dp-branes from Abelian Higgs sphalerons
我们考虑在拓扑结构为M^{p+1} x S^1的（p+2）维时空中的阿贝尔希格斯模型作为一个研究Dp膜上快子凝聚的场论玩具模型。该理论具有周期性的sphaleron解，其简正模方程类似于Lame型方程。这些方程是准精确可解的（QES）的希格斯玻色子的质量比的特定选择，因此有限数量的代数正规模式可以计算明确。我们计算了两个不同的希格斯玻色子质量比的值的快子势，并表明，在以前研究的纯标量场模型相比，在快子势和膜张力的最小值的负能量贡献之间的精确取消是可能的最简单的截断在膨胀的场周围的sphaleron。这进一步证明了Sen猜想的正确性。
There is a difficulty in defining the positions of the D-branes when the scalar fields on them are non-abelian. We show that we can use tachyon condensation to determine the position or the shape of D0-branes uniquely as a commutative region in spacetime together with non-trivial gauge flux on it, even if the scalar fields are non-abelian. We use the idea of the so-called coherent state method developed in the field of matrix models in the context of the tachyon condensation. We investigate configurations of noncommutative D2-brane made out of D0-branes as examples. In particular, we examine a…
We report the existence of a ghost- and tachyon-free sector in metric-affine theories of gravity, that is invariant under diffeomorphism and a particular abelian symmetry. In contrast with many studied cases in the literature, the constraints for unitarity and causality are granted by non-accidental symmetries and do not ask for further tuning, whose fate under renormalization would be unclear. Unsurprisingly, the minimal model is massless. We find that a mechanism to provide mass is accommodated by a simple Stueckelberg extension of metric-affine gravity involving the non-metricity tensor. A …
We explore various geometrical aspects of an action for six-dimensional chiral 2-forms based on the formalism of 1903.12196. We elucidate the coupling to general backgrounds and construct the full supersymmetric completion to an abelian (2,0) superconformal lagrangian including matter. We investigate the non-standard diffeomorphism properties of the fields and their relation to the hamiltonian formulation. We also test the action by considering compactifications on a circle, K3 and a Riemann surface. The results are consistent with expectations for an action describing the low-energy physics o…
In this paper we develop a phenomenological model inspired by QCD that mimics QCD theory. We use gauge theory in color dielectric medium ($G(ϕ)$) coupled with fermion fields to produce scalar and vector confinement in chromoelectric flux tube scenario. Abelian theory will be used to approximate the non-Abelian QCD theory in a consistent manner. We will calculate vector and scalar glueballs and compare the result to the existing simulation and experimental results and projections. The QCD-like vacuum associated with the model will be calculated and its behavior studied relative to changing quar…
We study string theory on $\mathbb{R}^d\times \mathbb{S}^1$. For applications to thermodynamics, the circumference of the $\mathbb{S}^1$ is the inverse temperature, $β$. We show that for $d=6$, the low energy effective field theory at the inverse Hagedorn temperature, $β=β_H$, has a one parameter family of normalizable spherically symmetric solutions that break the winding symmetry around the $\mathbb{S}^1$. The resulting backgrounds exhibit an enhanced symmetry, with the symmetry breaking pattern $SU(2)_L\times SU(2)_R\to SU(2)_{\rm diagonal}$. The effective field theory analysis of these bac…
We revisit the issue of the geometrical separability of the Hilbert space of physical states on lattice Abelian theories in the context of entanglement entropy. We discuss the conditions under which vectors in the Hilbert space, as well as the gauge invariant algebra, admit a tensor product decomposition with a geometrical interpretation. With the exception of pure gauge lattices with periodic boundary conditions which contain topological degrees of freedom, we show that the Hilbert space is geometrically separable.
A composite non-abelian model $SU(N) \times SU(N)$ is proposed as possible extension of the Yang-Mills symmetry. We obtain the corresponding gauge symmetry of the model and the most general lagrangian invariant by $SU(N) \times SU(N)$. The corresponding Feynman rules of the model are studied. Propagators and vertices are derived in the momentum space. As physical application, instead of considering the color symmetry $SU_{c}(3)$ for $QCD$ , we substitute it by the combination $SU_{c}(3) \times SU_{c}(3)$. It yields a possibility to go beyond $QCD$ symmetry in the sense that quarks are preserve…
