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{\bf Ji\v{r}\'{\i} Matou\v{s}ek and Robert \v{S}\'amal}
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{\bf Induced Trees in Triangle-Free Graphs}
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We prove that every connected triangle-free graph on $n$ vertices contains
an induced tree on $\exp(c\sqrt{\log n}\,)$ vertices, where $c$ is
a positive constant. The best known upper bound is $(2+o(1))\sqrt n$.
This partially answers questions of Erd\H{o}s, Saks, and S\'os and of Pultr.
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