John Arnold, the Houston billionaire who retired at 38 after leading one of the most successful hedge funds ever, has joined forces with Microsoft Corp. founder Bill Gates and other billionaires to invest in clean energy technology. The Breakthrough Energy Coalition was announced before the global climate summit in Paris that began Nov. 30. It includes Jeff Bezos, CEO and founder of Amazon.com Inc.; Richard Branson, CEO and founder of Virgin Group Ltd.; Mark Zuckerberg, CEO and founder of Facebook…