Four decades ago, a mathematician named Robert Merton used a math model to work out the price of stock options. Since then, physics, math, and engineering whizzes have flocked to finance. They’re known as  “quants” -- short for quantitative analysts – and they’ve been blamed for our current financial mess.  They designed the financial models and computer programs that were supposed to help investors manage risks. Critics have said that wrong assumptions in those models led to the current economic crisis. But that doesn’t mean quants are being shunned. In fact, talented people with technical backgrounds are more welcome than ever on Wall Street, according to former Goldman Sachs quant Petter Kolm.