Torsional Alfvén waves in solar magnetic flux tubes of axial symmetry K. Murawski, A. Solov’ev, Z. E. Musielak, A. K. Srivastava and J. Kraśkiewicz A&A, 577 (2015) A126 Published online: 18 May 2015 DOI: 10.1051/0004-6361/201424545