Yazar "Sahin, Bayram" seçeneğine göre listele

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    Anti-invariant Riemannian submersions from almost Hermitian manifolds
    (Versita, 2010) Sahin, Bayram
    We introduce anti-invariant Riemannian submersions from almost Hermitian manifolds onto Riemannian manifolds. We give an example, investigate the geometry of foliations which are arisen from the definition of a Riemannian submersion and check the harmonicity of such submersions. We also find necessary and sufficient conditions for a Langrangian Riemannian submersion, a special anti-invariant Riemannian submersion, to be totally geodesic. Moreover, we obtain decomposition theorems for the total manifold of such submersions.
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    Applications of lightlike geometry
    (Birkhauser Verlag Ag, 2010) Duggal, Krishan L.; Sahin, Bayram
    [Abstract Not Available]
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    Applications of lightlike hypersurfaces
    (Birkhauser Verlag Ag, 2010) Duggal, Krishan L.; Sahin, Bayram
    [Abstract Not Available]
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    BETA BEZIER CURVES
    (Ministry Communications & High Technologies Republic Azerbaijan, 2019) Levent, Akin; Sahin, Bayram
    In this paper, we investigate geometric properties of such curves. We construct a new curve by using curves based on new basis with beta functions satisfying various continuity condition and check shape properties. As an interesting property of such curves, we show that the curves based on new basis with beta functions do not have loops which is a useful property for CAGD systems. Since Pythagoren hodograph curves are also important in various CAD applications, we find certain conditions for Pythagorean Hodograph for the curves based on new basis with beta functions.
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    Biharmonic Riemannian maps
    (Polish Acad Sciences Inst Mathematics-Impan, 2011) Sahin, Bayram
    We give necessary and sufficient conditions for Riemannian maps to be biharmonic. We also define pseudo-umbilical Riemannian maps as a generalization of pseudo-umbilical submanifolds and show that such Riemannian maps put some restrictions on the target manifolds.
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    Chaki type pseudo-symmetric lightlike hypersurfaces
    (World Scientific Publ Co Pte Ltd, 2015) Sahin, Bayram; Yildiz, Ahmet
    In this paper, we investigate lightlike hypersurfaces which are Chaki type pseudosymmetric, Chaki type pseudo-Ricci symmetric and Chaki type pseudo-projective symmetric in a semi-Euclidean space. We also give some physical interpretations of Chaki type pseudo-symmetry condition.
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    CIRCLES ALONG A RIEMANNIAN MAP AND CLAIRAUT RIEMANNIAN MAPS
    (Korean Mathematical Soc, 2017) Sahin, Bayram
    We first extend Yano-Nomizu's theorem, which characterizes extrinsic spheres in a Riemannian manifold, for Riemannian maps. Then we introduce Clairaut Riemannian maps, give an example and obtain necessary and sufficient conditions for a Riemannian map to be Clairaut type.
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    Conformal anti-invariant submersions from almost Hermitian manifolds
    (Tubitak Scientific & Technological Research Council Turkey, 2016) Akyol, Mehmet Akif; Sahin, Bayram
    We introduce conformal anti-invariant submersions from almost Hermitian manifolds onto Riemannian manifolds. We give examples, investigate the geometry of foliations that arose from the definition of a conformal submersion, and find necessary and sufficient conditions for a conformal anti-invariant submersion to be totally geodesic. We also check the harmonicity of such submersions and show that the total space has certain product structures. Moreover, we obtain curvature relations between the base space and the total space, and find geometric implications of these relations.
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    Conformal Riemannian Maps between Riemannian Manifolds, Their Harmonicity and Decomposition Theorems
    (Springer, 2010) Sahin, Bayram
    Riemannian maps were introduced by Fischer (Contemp. Math. 132: 331-366, 1992) as a generalization isometric immersions and Riemannian submersions. He showed that such maps could be used to solve the generalized eikonal equation and to build a quantum model. On the other hand, horizontally conformal maps were defined by Fuglede (Ann. Inst. Fourier (Grenoble) 28: 107-144, 1978) and Ishihara (J. Math. Kyoto Univ. 19: 215229, 1979) and these maps are useful for characterization of harmonic morphisms. Horizontally conformal maps (conformal maps) have their applications in medical imaging (brain imaging) and computer graphics. In this paper, as a generalization of Riemannian maps and horizontally conformal submersions, we introduce conformal Riemannian maps, present examples and characterizations. We show that an application of conformal Riemannian maps can be made in weakening the horizontal conformal version of Hermann's theorem obtained by Okrut (Math. Notes 66(1): 94-104, 1999). We also give a geometric characterization of harmonic conformal Riemannian maps and obtain decomposition theorems by using the existence of conformal Riemannian maps.
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    Conformal semi-invariant submersions
    (World Scientific Publ Co Pte Ltd, 2017) Akyol, Mehmet Akif; Sahin, Bayram
    As a generalization of semi-invariant submersions, we introduce conformal semi-invariant submersions from almost Hermitian manifolds onto Riemannian manifolds. We give examples, investigate the geometry of foliations which arise from the definition of a conformal submersion and show that there are certain product structures on the total space of a conformal semi-invariant submersion. Moreover, we also check the harmonicity of such submersions and find necessary and sufficient conditions of a conformal semi-invariant submersion to be totally geodesic.
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    CONTACT HORIZONTALLY CONFORMAL SUBMERSIONS
    (De Gruyter Open Ltd, 2009) Sahin, Bayram
    Using the notion of horizontally conformal submersion, we generalize the contact metric submersions and obtain classification theorems for this submersion when the total manifold has some special almost contact structures.
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    CUBIC BEZIER-LIKE TRANSITION CURVES WITH NEW BASIS FUNCTIONS
    (Inst Mathematics & Mechanics, Natl Acad Sciences Azerbaijan, 2018) Levent, Akin; Sahin, Bayram
    A cubic trigonometric Bezier-like curve similar to the cubic Bezier curve, with a shape parameter, is presented in this work. With the suitable shape parameter, the cubic trigonometric Bezier-like curves can be made close to the cubic Bezier curves. Then we investigate the condition of smooth connection between non-adjacent cubic trigonometric Bezier-like curves.
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    EINSTEIN CONDITIONS FOR THE BASE SPACE OF ANTI-INVARIANT RIEMANNIAN SUBMERSIONS AND CLAIRAUT SUBMERSIONS
    (Mathematical Soc Rep China, 2015) Lee, Jungchan; Park, JeongHyeong; Sahin, Bayram; Song, Dae-Yup
    In this paper, we study the geometry of anti-invariant Riemannian submersions from a Kahler manifold onto a Riemannian manifold. We first determine the base space when the total space of an anti-invariant Riemannian submersion is Einstein and then we investigate new conditions for anti-invariant Riemannian submersions to be Clairaut submersions. We also focus on the geometry of Clairaut anti-invariant submersions.
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    Every Totally Umbilical Proper Slant Submanifold of a Kahler Manifold is Totally Geodesic
    (Birkhauser Verlag Ag, 2009) Sahin, Bayram
    We prove that there do not exist totally umbilical proper slant submanifolds in Kahler manifolds other than totally geodesic proper slant submanifolds.
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    Golden maps between Golden Riemannian manifolds and constancy of certain maps
    (Univ Osijek, Dept Mathematics, 2014) Sahin, Bayram; Akyol, Mehmet Akif
    We first introduce Golden maps between Golden Riemannian manifolds, give an example and show that such map is harmonic. Then we investigate the constancy of certain maps from Golden Riemannian manifolds to various manifolds by imposing the holomorphic-like map condition. Then we consider the reverse case and show that all such maps are constant.
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    Half-lightlike submanifolds
    (Birkhauser Verlag Ag, 2010) Duggal, Krishan L.; Sahin, Bayram
    [Abstract Not Available]
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    Half-lightlike submanifolds with planar normal sections in R24
    (Tubitak Scientific & Technological Research Council Turkey, 2014) Erdogan, Feyza Esra; Gunes, Rifat; Sahin, Bayram
    We investigate half-lightlike submanifolds with planar normal sections of 4-dimensional pseudo-Euclidean space. We obtain necessary and sufficient conditions for a half-lightlike submanifold of R-2(4) such that it has degenerate or nondegenerate planar normal sections.
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    Harmonic Riemannian maps on locally conformal Kaehler manifolds
    (Indian Acad Sciences, 2008) Sahin, Bayram
    We study harmonic Riemannian maps on locally conformal Kaehler manifolds (IcK manifolds). We show that if a Riemannian holomorphic map between IcK manifolds is harmonic, then the Lee vector field of the domain belongs to the kernel of the Riemannian map under a condition. When the domain is Kaehler, we prove that a Riemannian holomorphic map is harmonic if and only if the IcK manifold is Kaehler. Then we find similar results for Riemannian maps between IcK manifolds and Sasakian manifolds. Finally, We check the constancy of some maps between almost complex (or almost contact) manifolds and almost product manifolds.
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    Hemi-Slant Submersions
    (Springer Basel Ag, 2016) Tastan, Hakan Mete; Sahin, Bayram; Yanan, Sener
    As a generalization of anti-invariant submersions, semi-invariant submersions and slant submersions, we introduce the notion of hemi-slant submersion and study such submersions from Kahlerian manifolds onto Riemannian manifolds. After we study the geometry of leaves of distributions which are involved in the definition of the submersion, we obtain new conditions for such submersions to be harmonic and totally geodesic. Moreover, we give a characterization theorem for the proper hemi-slant submersions with totally umbilical fibers.
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    HOMOLOGY OF CONTACT CR-WARPED PRODUCT SUBMANIFOLDS OF AN ODD-DIMENSIONAL UNIT SPHERE
    (Korean Mathematical Soc, 2015) Sahin, Bayram; Sahin, Fulya
    We show that homology group on a contact CR-warped product submanifold in odd dimensional sphere is zero under certain conditions in terms of warping function and the dimension of the submanifold.