The boom in artificial intelligence risks widening inequality, with only a handful of companies and investors likely to reap its financial rewards, the BlackRock chief executive, Larry Fink, has said.The boss of the $14tn (£10.4tn) asset manager used his annual letter to investors on Monday to highlight potential hazards around the exponential growth in AI, which has attracted rapid investment and become, he said, “central to strategic competition” between global powers such as the US and China....