New stable phase of non-uniform charged black strings

Non-uniform black strings coupled to a gauge field are constructed by aperturbative method in a wide range of spacetime dimensions. At the linearorder of perturbations, we see that the Gregory-Laflamme instability vanishesat the point where the background solution becomes thermodynamically stable.The emergence/vanishing of the static mode resembles phase transitions, and infact we find that its critical exponent is nearly 1/2, which means asecond-order transition. By employing higher-order perturbations, the physicalproperties of the non-uniform black strings are investigated in detail. Forfixed spacetime dimensions, we find the critical charges at which the stabilityof non-uniform states changes. For some range of charge, non-uniform blackstrings are entropically favored over uniform ones. The gauge charge works as acontrol parameter that controls not only the stability of uniform black stringsbut also the non-uniform states. In addition, we find that for a fixedbackground charge the uniform state is not necessarily the state carrying thelargest tension. The phase diagram and a comparison with the critical dimensionare also discussed.Comment: 27 pages, 5 figures, references and minor comments are adde