Erdoğan, Damla
Even though surfaces are the most elementary objects in geometry and topology, because of the variety of structures they have it is still an active area of research. The symmetries of surfaces have been studied for a long time. One of the compelling questions is which of these symmetries can be extended to handlebodies and 3-sphere. In this thesis, we are focusing on the symmetries of surfaces which can be embedded into the symmetries of 3-sphere. The aim is to give an overview of the problem with some background and present some of the known results with proofs.


Dual metrics and nongeneric supersymmetries for a class of Siklos space-times
Baleanu, D; Baskal, S (2002-10-20)
The presence of Killing-Yano tensors implies the existence of nongeneric supercharges in spinning point particle theories on curved backgrounds. Dual metrics axe defined through their associated nondegenerate Killing tensors of valence two. Siklos space-times, which are the only nontrivial Einstein spares conformal to nonflat pp-waves are investigated with regard to the existence of their corresponding Killing and Killing-Yano, tensors. It is found that a class of Siklos space-times admit dual metrics and n...
On the errors arising in surface integral equations due to the discretization of the identity operatort
Ergül, Özgür Salih (2009-06-05)
Surface integral equations (SIEs) are commonly used to formulate scattering and radiation problems involving three-dimensional metallic and homogeneous dielectric objects with arbitrary shapes. For numerical solutions, equivalent electric and/or magnetic currents defined on surfaces are discretized and expanded in a series of basis functions. Then, the boundary conditions are tested on surfaces via a set of testing functions. Solutions of the resulting dense matrix equations provide the expansion coefficien...
Finite rigid sets in curve complexes of non-orientable surfaces
Ilbıra, Sabahattin; Korkmaz, Mustafa; Department of Mathematics (2017)
A finite rigid set in a curve complex of a surface is a subcomplex such that every locally injective simplicial map defined on this subcomplex into the curve complex is induced from an automorphism of curve complex. In this thesisi we find finite rigid sets in the curve complexes of connected, non-orientable surfaces of genus g with n holes, where g+n neq 4. 
On symplectic quotients of K3 surfaces
Cinkir, Z; Onsiper, H (Elsevier BV, 2000-12-18)
In this note, we construct generalized Shioda-Inose structures on K3 surfaces using cyclic covers and almost functoriality of Shioda-Inose structures with respect to normal subgroups of a given group of symplectic automorphisms.
Generalizing Allen's Theory of Time to Tree-Like Structures
Durhan, Salih; Sciavicco, Guido (2015-09-25)
Allen's Interval Algebra is one of the most prominent formalisms in the area of qualitative temporal (and, by extension, spatial) reasoning. However, its applications are naturally restricted to linear flows of time. While there is some recent work focused on studying relations between intervals (and also between intervals and points) on branching structures, there is no rigorous study of the first-order theory of branching time. In this paper, we approach this problem under a very general definition of tim...
Citation Formats
D. Erdoğan, “ON EXTENDING GROUP ACTIONS FROM SURFACES TO THREE SPHERE,” M.S. - Master of Science, Middle East Technical University, 2022.