Bose-Einstein Condensation of Pions in High Multiplicity Events

We present microcanonical ensemble calculations of particle number fluctuations in the ideal pion gas approaching Bose-Einstein condensation. In the samples of events with a fixed number of all pions, $N_{\pi}$, one may observe a prominent signal. When $N_{\pi}$ increases the scaled variances for particle number fluctuations of both neutral and charged pions increase dramatically in the vicinity of the Bose-Einstein condensation line. As an example, the estimates are presented for $p+p$ collisions at the beam energy of 70 GeV.