Index Cohesive Force Analysis Reveals That the US Market Became Prone to Systemic Collapses Since 2002 Kenett, Dror Y. ; Shapira, Yoash ; Madi, Asaf ; Bransburg-Zabary, Sharron ; Gur-Gershgoren, Gitit ; Ben-Jacob, Eshel Abstract Publication: PLoS ONE Pub Date: April 2011 DOI: 10.1371/journal.pone.0019378 Bibcode: 2011PLoSO...619378K