2001, Young-Gui Yoon and Steven G. Louie, “Electronic Structure and Quantum Conductance of Carbon Nanotubesâ€, in Giorgio Benedek et al. (editors), Nanostructured Carbon for Advanced Applications, Kluwer Academic Publishers, ISBN 978-0-7923-7042-0, page 242:If the intertube interactions are negligibly small, the electronic band structure along any line in the Brillouin zone parallel to the rope axis would be exactly the same as that of an isolated tube.
