  Measurements of event-by-event fluctuations of charged-particle
multiplicities in Pb-Pb collisions at $\sqrt{s_{\rm NN}}$ = 2.76 TeV using the
ALICE detector at the CERN Large Hadron Collider (LHC) are presented in the
pseudorapidity range $|\eta|<0.8$ and transverse momentum $0.2 < p_{\rm T} <
2.0$ GeV/$c$. The amplitude of the fluctuations is expressed in terms of the
variance normalized by the mean of the multiplicity distribution. The $\eta$
and $p_{\rm T}$ dependences of the fluctuations and their evolution with
respect to collision centrality are investigated. The multiplicity fluctuations
tend to decrease from peripheral to central collisions. The results are
compared to those obtained from HIJING and AMPT Monte Carlo event generators as
well as to experimental data at lower collision energies. Additionally, the
measured multiplicity fluctuations are discussed in the context of the
isothermal compressibility of the high-density strongly-interacting system
formed in central Pb-Pb collisions.
