Higher dimensional Bell-Szekeres metric

Şentürk, Çetin


Transient wave propagation in anisotropic multilayered media
Mesutgil, Serdar; Turhan, Doğan; Department of Engineering Sciences (2003)
Kaluza-klein reduction of higher curvature gravity models
Kuyrukcu, Halil; Başkal, Sibel; Department of Physics (2010)
The standard Kaluza-Klein theory is reviewed and its basic equations are rewritten in an anholonomic basis. A five dimensional Yang-Mills type quadratic and cubic curvature gravity model is introduced. By employing the Palatini variational principle, the field equations and the stress-energy tensors of these models are presented. Unification of gravity with electromagnetism is achieved through the Kaluza-Klein reduction mechanism. Reduced curvature invariants,field equations and stress-energy tensors in fou...
Deep-trench RIE optimization for high performance MEMS microsensors
Aydemir, Akın; Turan, Raşit; Department of Physics (2007)
This thesis presents the optimization of deep reactive ion etching process (DRIE) to achieve high precision 3-dimensional integrated micro electro mechanical systems (MEMS) sensors with high aspect ratio structures. Two optimization processes have been performed to achieve 20 μm depth for 1 μm opening for a dissolved wafer process (DWP) and to achieve 100 μm depth for 1 μm opening for silicon-on-glass (SOG) process. A number of parameters affecting the etch rate and profile angle are investigated, including...
Design and realization of high power low loss combiners
Suna, Gonca; Yıldırım, Nevzat; Department of Electrical and Electronics Engineering (2013)
In recent high power microwave systems, power generation is commonly achieved by combining a bunch of transistor amplifier. Regarding the efficiency of power combining operation, insertion loss of the combiner is a critical parameter. In this thesis, several low loss power combiners, namely, microstrip Wilkinson combiner in 6-18 GHz frequency range, suspended stripline branchline couplers in 16.5-17.5 GHz frequency range and finally, planar probe coaxial waveguide combiners in 8.5- 11.5 GHz and 15.5-17.5 GH...
Development of software for calculations of the reflectance, transmittance and absorptance of multilayered thin films
Şimşek, Yusuf; Esendemir, Akif; Department of Physics (2008)
The aim of this study is to develop a software which calculates reflection, transmission and absorption of multilayered thin films by using complex indices of refraction, as a function of both wavelength and thickness. For these calculations matrix methods will be considered and this software is programmed with the matrix method. Outputs of the program will be compared with the theoretical and experimental results studied in the scientific papers.
Citation Formats
Ç. Şentürk, “Higher dimensional Bell-Szekeres metric,” M.S. - Master of Science, Middle East Technical University, 2003.