Abstract:
We study (non-)integrability and the presence of chaos in gravity dual backgrounds of
strongly coupled gauge theories with unquenched
avor, speci cally of the four-dimensional
N = 2 super Yang-Mills theory and the three-dimensional ABJM theory. By examining string
motion on the geometries corresponding to backreacted D3/D7 and D2/D6 systems, we show
that integrable theories with quenched
avor become non-integrable when the virtual quark
loops are taken into account. For the string solutions in the backreacted D3/D7 system, we
compute the leading Lyapunov exponent which turns out to saturate to a positive value as the
number of
avors increases. The exponent depends very weakly on the number of
avors when
they approach the number of colors. This suggests that once a particular
avor number in the
theory is reached, a further increase does not lead to more severe chaotic phenomena, implying
certain saturation e ects on chaos.
