We derive lens distortion and magnification profiles of four well known clusters observed with Subaru .
Each cluster is very well fitted by the general form predicted for Cold Dark Matter ( CDM ) dominated halos , with good consistency found between the independent distortion and magnification measurements .
The inferred level of mass concentration is surprisingly high , 8 < c _ { vir } < 15 ( \langle c _ { vir } \rangle = 10.39 \pm 0.91 ) , compared to the relatively shallow profiles predicted by the \Lambda CDM model , c _ { vir } = 5.06 \pm 1.10 ( for \langle M _ { vir } \rangle = 1.25 \times 10 ^ { 15 } M _ { \odot } / h ) .
This represents a 4 \sigma discrepancy , and includes the relatively modest effects of projection bias and profile evolution derived from N-body simulations , which oppose each other with little residual effect .
In the context of CDM based cosmologies , this discrepancy implies clusters collapse earlier ( z \geq 1 ) than predicted ( z < 0.5 ) , when the Universe was correspondingly denser .