SOME SPECIAL CURVES BELONGING TO MANNHEIM CURVES PAIR Süleyman Şenyurt*1, Yasin Altun2, Ceyda Cevahir3and Hüseyin Kocayiğit4 *1,2,3 Ordu University, Faculty of Art and Science, Ordu, Turkey 4Manisa Celal Bayar University, Faculty of Education, Manisa,Turkey * Correspondig Author: E-mail: [email protected] In this paper, we investigate special Smarandache curves with regard to Sabban frame for Mannheim partner curve spherical indicatrix. We created Sabban frame belonging to this curves. It was explained Smarandache curves position vector is consisted by Sabban vectors belonging to this curves. Then, we calculated geodesic curvatures of this Smarandache curves. Found results were expressed depending on the Mannheim curve. Key Words: Mannheim curve pair, Smarandache curve, Sabban frame, Geodesic curvature. 1. Introduction In differential geometry, special curves have an important role. One of these curves Mannheim curves. Mannheim curve was firstly defined by A. Mannheim in 1878. Any curve can be a Mannheim curve if and only if = , is a nonzere constant, where curvature of curve is and curvature 2 2 of torsion is . After a time, Mannheim curve was redefined by Liu and Wang. According to this new definition, when first curves principal normal vector and second curves binormal vector are linearly dependent, first curve was named as Mannheim curve, and second curve was named as Mannheim partner curve [8]. We can found many studies in literature related to Mannheim curves [4, 9]. A regular curve in Minkowski space-time, whose position vector is composed by Frenet frame vectors regular curve is called a Smarandache curve [15]. Special Smarandache curves have been studied by some authors [1, 2, 5, 10, 11]. K. Taşköprü, M. Tosun studied special Smarandache curves according to Sabban frame on S2 [14]. S. Şenyurt and A. Çalışkan investigated special Smarandache curves in terms of Sabban frame of spherical indicatrix curves and they gave some characterization of Smarandache curves [3]. We investigated special Smarandache curves belonging to Sabban frame drawn on the surface of the sphere by Darboux vector of involute and Bertrand partner curves [12, 13]. Let :I E3 be a unit speed curve, we defined the quantities of the Frenet frame and Frenet formulae, respectively [7], (s) T(s)=(s),N(s)= ,B(s)=T(s)N(s), (1.1) (s) T(s)=(s)N(s),N(s)=(s)T(s)(s)B(s),B(s)=(s)N(s). (1.2) Let , be Mannheim pair curve and Frenet apparatus {T(s),N(s),B(s),(s),(s)} and {T(s),N(s),B(s),(s),(s)} are respectively. The relation between the Frenet apparatus are as follows, [9], T =cosT sinB, N =sinT cosB,B = N, = , = (1.3) W 1 Let :I S2 be a unit speed spherical curve. We denote s as the arc-length parameter of . Let us denote by (s)=(s), t(s)=(s), d(s)=(s)t(s) (1.4) {(s),t(s),d(s)} frame is called the Sabban frame of on S2. Then we have the following spherical Frenet formulae of (s)=t(s), t(s)=(s) (s)d(s), d(s)= (s)t(s) g g (1.5) where is called the geodesic curvature of the curve on S2 which is g (s)=t(s),d(s). (1.6) g 2. Main Results In this section, we investigated special Smarandache curves such as created by Sabban frame, {T,T ,T T }, {N,T ,N T } and {B,T ,BT }. We will find some results. These T T N N B B results will be expressed depending on the Mannheim curve. Let’s find results on this Smarandache curves. (s )=T(s), (s )= N(s) and (s )= B(s) be a regular spherical T N B T N B curves on S2The Sabban frames of spherical indicatrix belonging to Mannheim partner curve are as follows: T =T,T = N,TT = B, (2.1) T T N = N, T =cosTsinB, NT =sinTcosB, (2.2) N N B = B, T =N, BT =T. (2.3) B B From the equation (1.5), the spherical Frenet formulae of (T), (N) and (B) are, respectively, T'=T , T '=T TT , (TT )= T , (2.4) T T T T T ' ' N'=T ,T '=N NT ,(NT )= T , (2.5) N N W N N W N B'=T ,T '=B BT ,(BT )= T . (2.6) B B B B B Using the equation (1.6) the geodesic curvatures of (T), (N) and (B) are, ' T N B = , = and = . (2.7) g g W g Definition 2.1. Let (T) curve be of , T and T be unit vector of (T). In this case - 1 T Smarandache curve can be defined by 1 (s)= (TT ). (2.8) 1 2 T Theorem 2.1. The 1 geodesic curvature belonging to -Smarandache curve of the Mannheim g 1 1 W W curve is 1 = ( 2), where g W 5 1 2 3 (2( )2)2 2 W W W W W W W =2( )2 ( )( ), =23( )2 ( )4 ( )( ) 1 2 W W W =2( )( )3( ). 3 1 Proof:. (s )= (TT ) and from the equation (2.1), we can write 1 T 2 T 1 (s)= (TN). (2.9) 1 2 Differentiating (2.9), T (s) is 1 1 T (s)= (T N B). (2.10) 1 2( )2 Considering the equations (2.9) and (2.10), with ease seen that 1 (T )(s)= ( T N2B). (2.11) 1 1 42( )2 Differentiating (2.10) equation, T ' vector is 1 2 T '(s)= (TNB), (2.12) 1 1 2 3 (2( )2)2 where coefficients are =2( )2 ( )( ), 1 =23( )2 ( )4 ( )( ), (2.13) 2 =2( )( )3( ). 3 From the equation (1.6), (2.11) and (2.12), 1 geodesic curvature of (s) is g 1 1 1 = ( 2). (2.14) g 5 1 2 3 (2( )2)2 Substituting the equations (1.3) into equation (2.9), (2.10), (2.11) and (2.12), Sabban apparatus of the -Smarandache curve for Mannheim curve are 1 1 (s)= ((sincos)T (cossin)B), 1 2 (sincos) W (cossin) T (s)= T N B, 1 W 2 22 W 2 22 W 2 22 W (cossin) 2 W (cossin) (T )(s)= T N B, 1 1 2 W 2 42 2 W 2 42 2 W 2 42 3 ()4 2(cos sin) ()4 2 ()4 2( cossin) T '(s)= 1 2 T 3 N 2 1 B 1 (W 222)2 (W 222)2 (W 222)2 and 1 geodesic curvature is g 1 W W 1 = ( 2). g W 5 1 2 3 (2( )2)2 Definition 2.2. Let (T) curve be of , T and TT be unit vector of (T). In this case - 2 T T Smarandache curve can be defined by 1 (s)= (T TT ). (2.15) 2 2 T T Theorem 2.2. The 2 geodesic curvature belonging to -Smarandache curve of the Mannheim g 2 1 W curve is 2 = (2 ), where g W 5 1 2 3 (12( )2)2 W W W W W W W =( )2( )32( )( ), =13( )2 2( )4 ( ) 1 2 W W W =( )2 2( )4 ( ). 3 Proof: From the equations (1.3), (2.1) and (2.15), we can write 1 (s)= (sinT N cosB). 2 2 Herein, if Sabban apparatus calculate cos W sin W sin W cos T (s)= T N B, 2 2 W 22 2 W 22 2 W 22 ()4 2( sin cos) ()4 2 ()4 2( cos sin) T '(s)= 2 1 T 3 N 2 1 B, 2 2(W 2 2)2 (2 W 2 2)2 (2 W 2 2)2 2 W cossin 2 W sincos ( T )(s)= T N B, 2 2 4 W 2 22 4 W 2 22 4 W 2 22 2 geodesic curvature is g 1 W 2 = (2 ). g W 5 1 2 3 (12( )2)2 Definition 2.3. Let (T) curve be of , T, T and TT be unit vector of (T). In this case T T -Smarandache curve can be defined by 3 1 (s)= (TT TT ). (2.16) 3 3 T T 4 Theorem 2.3 The 3 geodesic curvature belonging to -Smarandache curve of the Mannheim g 3 1 curve is 3 = ((2 1) (1 ) (2 )), where g 5 W 1 W 2 W 3 4 2(1 ( )2)2 W W W W W W W =24( )4( )2 2( )3( )(2 1) 1 W W W W W W =22( )4( )2 ( )32( )4 ( )(1 ) 2 W W W W W W =2( )4( )2 4( )32( )4 ( )(2 ). 3 Proof: From the equations (1.3),(2.1) and (2.16), we can write 1 (s)= ((sincos)T N (cossin)B). 3 3 Then if Sabban apparatus calculate cos(W )sin W sin(W )cos T (s)= T N B, 3 2(W 2 W 2) 2(W 2 W 2) 2(W 2 W 2) ()4 3( sincos) ()4 3 T '(s)= 2 1 T 3 N 3 4(W 2 W 2)2 4(W 2 W 2)2 ()4 3( cossin) 2 1 B, 4(W 2 W 2)2 (2 W )cos(W )sin 2 W ( T )(s)= T N 3 3 6 W 2 6 W 62 6 W 2 6 W 62 (2 W )sin(W )cos B, 6 W 2 6 W 62 3 geodesic curvature is g 1 W W W 3 = ((2 1) (1 ) (2 )). g W W 5 1 2 3 4 2(1 ( )2)2 Definition 2.4. Let (N) curve be of , N and T be unit vector of (N). In this case - 4 N Smarandache curve can be defined by 1 (s)= (NT ). (2.17) 4 4 N Theorem 2.4. The 4 geodesic curvature belonging to -Smarandache curve of the Mannheim g 4 1 W curve is 4 = ( 2), where =( ) csc and g (22)52 1 2 3 ()2 W 2 =22 , =232 4 , =23. 1 2 3 5 Proof: From the equations (1.3), (2.2) and (2.17), we can say 2 W 2 sincos W sin 2 W 2 cos (s)= T N B. 4 22 2 W 2 22 2 W 2 22 2 W 2 If Sabban apparatus calculate (W )cos W 2 2 sin W T (s)= T N 4 W 2 2 22 W 2 2 22 (W )sin W 2 2 cos B, W 2 2 22 ( W ) 2cos 2 W 2 22sin ( W ) 2 T '(s)= 3 2 1 T 3 2 N 4 (22)2 W 2 2 (22)2 W 2 2 ( W ) 2sin 2 W 2 22 cos 2 3 1 B, (22)2 W 2 2 (2 W )cos W 2 2 sin 2W ( T )(s)= T N 4 4 422 W 2 2 422 W 2 2 (2 W )sin W 2 2 cos B, 422 W 2 2 4 geodesic curvature is g 1 4 = ( 2). g 5 1 2 3 (22)2 Definition 2.5. Let (N) curve be of , T and N T be unit vector of (N). In this case 5 N N -Smarandache curve can be defined by 1 (s)= (T NT ). (2.18) 5 2 N N Theorem 2.5. The 5 geodesic curvature belonging to -Smarandache curve of the Mannheim g 5 1 curve is 5 = (2 ), where g 5 1 2 3 (22)2 =232, =132 24 , =2 24 1 2 3 Proof: From the equations (1.3),(2.2) and (2.18), we can write (W )cos W ( W )sin (s)= T N B. 5 22 2 W 2 22 2 W 2 22 2 W 2 6 Here, if Sabban apparatus calculate (W )cos W 2 2 sin ( W ) T (s)= T N 5 122 W 2 2 122 W 2 2 (W )sin W 2 2 cos B, 122 W 2 2 ( W ) 2cos 2 W 2 22 sin ( W ) 2 3 2 1 3 2 T '(s)= T N 5 (122)2 2 W 2 (122)2 2 W 2 ( W ) 2sin 2 W 2 22 cos 2 3 1 B, (122)2 2 W 2 (W )cos2 W 2 2 sin W ( T )(s)= T N 5 5 242 W 2 2 242 W 2 2 2 W 2 2 cos(W )sin B, 242 W 2 2 5 geodesic curvature is g 1 5 = (2 ). g 5 1 2 3 (22)2 Definition 2.6 Let (N) curve be of , N, T and N T be unit vector of (N). In this N N case -Smarandache curve can be defined by 6 1 (s)= (NT NT ). (2.19) 6 3 N N Theorem 2.6 The 6 geodesic curvature belonging to -Smarandache curve of the Mannheim g 6 (21) (1) (2) curve is 6 = 1 2 3 ,where g 5 4 2(12)2 =2442 232(21), =2242 2324 (1), 1 2 =242 4324 (2). 3 Proof: From the equations (1.3), (2.2) and (2.19), we can write (W )cos 2 W 2 sin W (s)= T N 6 32 3 W 2 32 3 W 2 ( W )sin 2 W 2 cos B. 32 3 W 2 Herein, if Sabban apparatus calculate 7 (W (1))cos W 2 2 sin (1) W T (s)= T N 6 2(12) W 2 2 2(12) W 2 2 ((1)W )sin W 2 2 cos B, 2(12) W 2 2 ( W ) 3cos 3 W 232 sin ( W ) 3 T '(s)= 3 2 1 T 3 2 N 6 4(12)2 2 W 2 4(12)2 2 W 2 ( W ) 3sin 3 W 2 32 cos 2 3 1 B, 4(12)2 2 W 2 ((2) W (1))cos(21) W 2 2 sin ( T )(s)= T 6 6 6662 W 2 2 (2)(1) W N 6662 W 2 2 (21) W 2 2 cos((2) W (1))sin B, 6662 W 2 2 6 geodesic curvature is g (21) (1) (2) 6 = 1 2 3. g 5 4 2(12)2 Definition 2.7. Let (B) curve be of , T and B T be unit vector of (B). In this case - 7 B B Smarandache curve can be defined by 1 (s)= (T TT ). (2.20) 7 2 B B Theorem 2.7. The 7 geodesic curvature belonging to -Smarandache curve of the Mannheim g 7 1 curve is 7 = (2 ), where g 5 W 1 2 3 (12( )2)2 W =( )( )32( )( ), =13( )22( )4( ) 1 W W W W 2 W W W =( )22( )4( ). 3 W W W Proof: From the equations (1.3), (2.3) and (2.20), we can write 1 (s)= (sinT N cosB). 7 2 If Sabban apparatus calculate 8 cos W sin W sin W cos T (s)= T N B, 7 2 W 2 2 2 W 2 2 2 W 2 2 4 4 4 W 2( cos sin) W 2 W 2( cossin) 3 2 1 2 3 T '(s)= T N B, 7 (2 W 2 2)2 (2 W 2 2)2 (2 W 2 2)2 2 W cossin cos2 W sin ( T )(s)= T N B, 7 7 4 W 2 22 4 W 2 22 4 W 2 22 7 geodesic curvature is g 1 7 = ( 2). g 5 W 1 W 2 3 (2( )2)2 W Definition 2.8. Let (B) curve be of , B, T and B T be unit vector of (B). In this case B B -Smarandache curve can be defined by 8 1 (s)= (BT BT ). (2.21) 8 3 B B Theorem 2.8. The 8 geodesic curvature belonging to -Smarandache curve of the Mannheim g 8 1 curve is 8 = ((2 1) (1 ) (2 ) ), where g 5 W 1 W 2 W 3 4 2(1 ( )2)2 W W =24 4( )( )22( )3( )(2 1) 1 W W W W W W =22 4( )2( )32( )4( )(1 ) 2 W W W W W W =2 4( )24( )32( )4( )(2 ). 3 W W W W W W Proof: From the equations (1.3), (2.3) and (2.21), we can write 1 (s)= ((cossin)T N (cossin)B). 8 3 Here if Sabban apparatus calculate cos( W )sin W sin( W )cos T (s)= T N B, 8 2(W 2 W 2) 2(W 2 W 2) 2(W 2 W 2) 4 4 4 W 3( cos sin) W 3 W 3( cos sin) T '(s)= 3 2 T 1 N 2 3 B, 8 4(W 2 W 2)2 4(W 2 W 2)2 4(W 2 W 2)2 (2 W )cos(W )sin 2 W ( T )(s)= T N 8 8 6 W 2 6 W 62 6 W 2 6 W 62 (W )cos(2 W )sin B, 6 W 2 6 W 62 8 geodesic curvature is g 9 1 8 = ((2 1) (1 ) (2 ) ). g 5 W 1 W 2 W 3 4 2(1 ( )2)2 W W 3. Conclusion In this study, we studied Mannheim Partner Curves and Smarandache curves, which are well known in Differential Geometry. The Sabban frames of the differential curves drawn by the Frenet vectors of the Mannheim Partner Curve on the unit sphere surface were calculated. Then Smarandache curves were defined with the help of these frames. Finally, geodesic curvatures of these curves were calculated according to Sabban frames. References [1] A. T. Ali, Special Smarandache curves in the Euclidian Space, International Journal of Mathematical Combinatorics 2 (2010), pp.30-36 [2] Ö. Bektaş, S. Yüce, Special Smarandache curves according to Darboux Frame in Euclidean 3- Space, Romanian Journal of Mathematics and Computer Sciencel, 3 (2013), 1, pp. 48-59 [3] A. Çalışkan S. Şenyurt, Smarandache curves in terms of Sabban frame of spherical indicatrix curves, Gen. Math. Notes 31 (2015), 2, pp.1-15 [4] A. Çalışkan , S.Şenyurt, NC-Smarandache curves of Mannheim curve couple according to Frenet Frame, International Journal of Mathematical Combinatorics 1(2015), pp. 1-13. [5] M. Çetin, Y. Tuncer, M. K. Karacan, Smarandache curves according to Bishop frame in Euclidean 3-Space, Gen. Math. Notes, 20 (2014), pp. 50-66 [6] W. Fenchel, On the Differential Geometry of closed space curves, Bulletin of the American Mathematical Society, 57 (1951), pp.44-54 [7] H. H. Hacısalihoğlu, Differential Geometry, Academic Press Inc. Ankara, 1994. [8] H. Liu, F. Wang, Mannheim partner curves in 3-space, Journal of Geometry, 88 (2008) ,(1-2), pp. 120-126 [9] K. Orbay, E. Kasap, On Mannheim partner curves in , International Journal of Physical Sciences, 4 (2009), 5, pp. 261-264 [10] M. Elzawy, Smarandache curves in Euclidian 4-space E4, Journal of the Eqyptian Mathematical Society (in press), DOI: http://dx.doi.org/10.1016/j.joems [11] S. Senyurt, S. Sivas, An application of Smarandache curve, University of Ordu Journal of Science and Technology, 3 (2013), 1, pp.46-60 [12] S. Şenyurt, Y. Altun, C. Cevahir, Smarandache Curves According to Sabban Frame of Fixed Pole Curve Belonging to The Bertrand Curves Pair, AIP Conf. Proc. 1726 (2016) doi:10.1063/1.4945871. [13] S. Şenyurt , Y. Altun , C. Cevahir, On The Darboux Vector Belonging to Involute Curve A Different View, Mathematical Sciences and Applications E-Notes, 4 (2016), 2, pp. 121-130. [14] K. Taşköprü, M. Tosun, Smarandache Curves on S2, Boletim da Sociedade Paranaense de Matematica 3 Srie., 32 (2014), 1, pp. 51-59 [15] M. Turgut, S. Ylmaz, Smarandache curves in Minkowski space-time, International Journal of Mathematical Combinatorics, 3 (2008) pp.51-55 10