BUHEP-96-39 hep-ph/9610201 Binary String Dynamics 1 ;a 1 ;b Indranil Dasgupta and Ry an Rohm a Boston Univ ersit y , Boston, Ma 02215, USA b Univ ersit y of North Carolina, Chap el Hill, NC 27599, USA In this pap er w e in v estigate the dynamical prop erties of binary cosmic strings [1]. W e nd extrinsic curv ature dep endence of the string action and sho w that kinks on binary strinks are ero ded while cusps can pla y a ma jor role in their ev olution. Septem ber 26, 1996 1 e-mail: ******@budo du, r ******@ du 1. In tro duction In a recen t pap er [1] it w as sho wn that the cosmic string solutions of some grand- uni ed theories ha v e a microscopic structure whic h is not cylindrically symmetric, but instead is attened, giving rise to a preferred transv erse direction. In this pap er w e in- v estigate the dynamical prop erties of these binary cosmic strings. W e b egin b y deriving an e ectiv e action for the binary string, using an appro ximation whereb y t w ow orldsheets de ned b y the cores of the t w o p onen ts are tak en to ha v e constan t (spacelik e) separation. Describing the p onen ts b y the Nam bu-Goto action, w e then express the result in terms of one w orldsheet, with a transv erse spacelik e v ector determining the separation of p onen t strings. The classical equations obtained in this descriptio
