حاولنا في هذا البحث أن نناقش خاصية العالمية لأي نظام حقل متحول في الزمن الموسع حول الخلفيات pp-wave. وفقا لهذه الخاصية، يتبين أن الكثافة الزمنية للأرضية المقياسة على مجموعة محددة من التكوينات الحقلية، التي تسمى القطاع العالمي، هي نفسها حول جميع الpp-waves، حتى خارج الجهد، مع نفس الفضاء الأفقي ونفس الملامح للخلفيات المقياسة. في هذا البحث، نقتصر تحليلنا على الحقول التنسيبية فقط. في سياق نظرية الحبل البوزوني، ننظر إلى الpp-waves على جهد الخط ونحتج على وجود قطاع عالمي لمشاكل الورك شيت الذي يكون لا حساس لطبيعة المتريك الpp-wave والسيطرة الخلفية. يمكن أيضا أن يتم إعادة إنشاء هذه النتائج باستخدام نظرية الحقل التطبيقي الورك شيت. كما ندرس هذه الpp-waves في نظرية الحبل الإغلاق الغير المعادلي. وبالخصوص، نحتج على أن نقول أن الإجابة الpp-wave خارج الجهد مع الفضاء الأفقي المستقيم والديلاتون غير معتمد على الإحداثيات الأفقية يتم تحويلها بحد أقصى بطريقة مربعة في الحقول. وبسبب هذه البساطة، يتوقع أن الpp-waves خارج الجهد يمكن أن يتم التعرف عليها في الجانبين. بالإضافة إلى ذلك، تم النقاش في هذا البحث بشأن طريقة تكرارية لحساب الطوابق المتوسطة العالية باستخدام معادلات نظرية الحبل الإغلاق الحقل. يمكن توسيع كل تحليلات نظرية الحبل البوزوني التي قمنا بها في هذا البحث إلى القطاع المشترك Neveu-Schwarz للحبل السوبر.
We discuss a universality property of any covariant field theory in space-time expanded around pp-wave backgrounds. According to this property the space-time lagrangian density evaluated on a restricted set of field configurations, called universal sector, turns out to be same around all the pp-waves, even off-shell, with same transverse space and same profiles for the background scalars. In this paper we restrict our discussion to tensorial fields only. In the context of bosonic string theory we consider on-shell pp-waves and argue that universality requires the existence of a universal sector of world-sheet operators whose correlation functions are insensitive to the pp-wave nature of the metric and the background gauge flux. Such results can also be reproduced using the world-sheet conformal field theory. We also study such pp-waves in non-polynomial closed string field theory (CSFT). In particular, we argue that for an off-shell pp-wave ansatz with flat transverse space and dilaton independent of transverse coordinates the field redefinition relating the low energy effective field theory and CSFT with all the massive modes integrated out is at most quadratic in fields. Because of this simplification it is expected that the off-shell pp-waves can be identified on the two sides. Furthermore, given the massless pp-wave field configurations, an iterative method for computing the higher massive modes using the CSFT equations of motion has been discussed. All our bosonic string theory analyses can be generalised to the common Neveu-Schwarz sector of superstrings.
We find new exact solutions of the Abelian-Higgs model coupled to General Relativity, characterized by a non-vanishing superconducting current. The solutions correspond to textit{pp}-waves, AdS waves, and Kundt spaces, for which both the Maxwell field and the gradient of the phase of the scalar are aligned with the null direction defining these spaces. In the Kundt family, the geometry of the two-dimensional surfaces orthogonal to the superconducting current is determined by the solutions of the two-dimensional Liouville equation, and in consequence, these surfaces are of constant curvature, as it occurs in a vacuum. The solution to the Liouville equation also acts as a potential for the Maxwell field, which we integrate into a closed-form. Using these results, we show that the combined effects of the gravitational and scalar interactions can confine the electromagnetic field within a bounded region in the surfaces transverse to the current.
The most general parallelizable pp-wave backgrounds which are non-dilatonic solutions in the NS-NS sector of type IIA and IIB string theories are considered. We demonstrate that parallelizable pp-wave backgrounds are necessarily homogeneous plane-waves, and that a large class of homogeneous plane-waves are parallelizable, stating the necessary conditions. Such plane-waves can be classified according to the number of preserved supersymmetries. In type IIA, these include backgrounds preserving 16, 18, 20, 22 and 24 supercharges, while in the IIB case they preserve 16, 20, 24 or 28 supercharges. An intriguing property of parallelizable pp-wave backgrounds is that the bosonic part of these solutions are invariant under T-duality, while the number of supercharges might change under T-duality. Due to their alpha exactness, they provide interesting backgrounds for studying string theory. Quantization of string modes, their compactification and behaviour under T-duality are studied. In addition, we consider BPS $Dp$-branes, and show that these $Dp$-branes can be classified in terms of the locations of their world volumes with respect to the background $H$-field.
We present the Penrose limits of a complex marginal deformation of $AdS_5times S^5$, which incorporates the $SL(2,mathbb{R})$ symmetry of type IIB theory, along the $(J,0,0)$ geodesic and along the $(J,J,J)$ geodesic. We discuss giant gravitons on the deformed $(J,0,0)$ pp-wave background.
We study a new class of inhomogeneous pp-wave solutions with 8 unbroken supersymmetries in D=11 supergravity. The 9 dimensional transverse space is Euclidean and split into 3 and 6 dimensional subspaces. The solutions have non-constant gauge flux, which are described in terms of an arbitrary holomorphic function of the complexified 6 dimensional space. The supermembrane and matrix theory descriptions are also provided and we identify the relevant supersymmetry transformation rules. The action also arises through a dimensional reduction of N=1, D=4 supersymmetric Yang-Mills theory coupled to 3 gauge adjoint and chiral multiplets, whose interactions are determined by the holomorphic function of the supergravity solution now constituting the superpotential.
We consider the geodesic equation in impulsive pp-wave space-times in Rosen form, where the metric is of Lipschitz regularity. We prove that the geodesics (in the sense of Caratheodory) are actually continuously differentiable, thereby rigorously justifying the $C^1$-matching procedure which has been used in the literature to explicitly derive the geodesics in space-times of this form.