We examine how the statistics of the quadrupoles of ( projected ) cluster masses can discriminate between flat cold dark matter ( CDM ) universes with or without a cosmological constant term .
Even in the era of high precision cosmology that cosmic microwave background experiments should open soon , it is important to devise self consistency tests of cosmogonic theories tuned at the matter radiation decoupling epoch using data from the non–linear evolved universe .
We build cluster catalogs from two large volume simulations of a “ tilted ” CDM model and a \Lambda CDM model with cosmic density parameter \Omega _ { m } = 0.35 and cosmological constant contribution \Omega _ { \Lambda } = 0.65 .
From the projected mass distribution of the clusters we work out the quadrupoles Q and examine their dependence on cluster mass and the cosmological model .
We find that TCDM clusters have systematically larger quadrupoles than their \Lambda CDM counterpart .
The effect is mass dependent : massive clusters ( M \raise - 4.0 pt \hbox { \hbox to 0.0 pt { \hbox { $ \sim$ } } \raise 5.0 pt \hbox { $ > $ } } 10 ^ { 1 % 5 } { h ^ { -1 } M _ { \odot } } ) have quadrupoles differing by more than 30 % in the two models , while for M \raise - 2.0 pt \hbox { \hbox to 0.0 pt { \hbox { $ \sim$ } } \raise 5.0 pt \hbox { $ < $ } } 4 % \times 10 ^ { 14 } { h ^ { -1 } M _ { \odot } } the difference rapidly drops to \sim 1 % .
Performing a K-S test of the Q distributions , we estimate that using just the 15 most massive clusters in the simulation volume ( 360 h ^ { -1 } { Mpc } a side ) we can discriminate between TCDM and \Lambda CDM at a confidence level better than 99.9 % .
In the volume probed by exhisting observations , there are potentially several hundred clusters with masses above the threshold for which the differences in the quadrupoles become relevant .
Should weak lensing data become available for this whole set , a quadrupole analysis may be expected to discriminate among different values of \Lambda .

PACS : 95.35 ; 98.80 ; 98.65.Cw