LONDON (AP) — With a smile that lit up TV screens around the world, Kate Middleton swept down the aisle to marry Prince William in a union expected to revitalize the British monarchy. Hundreds of thousands then cheered as the royal couple rode an open carriage to Buckingham Palace. Even with millions of people tuning in to watch, the couple managed to appear at times in their own private world Friday, both at Westminster Abbey and on the balcony of Buckingham Palace.