What is the name of the Imperial capital city-planet after the Republic becomes the Empire?

The story behind the answer

The city-covered world that hosted the Galactic Senate remains the seat of power when Palpatine transforms the Republic into the Empire, even being dubbed “Imperial Center” in some sources. Naboo is Palpatine’s and Padmé’s picturesque homeworld, not the galactic capital; Alderaan is a pacifist Core World later destroyed by the Death Star; and Corellia is famed for shipyards and as Han Solo’s birthplace.

As an ecumenopolis, the capital’s entire surface is urbanized, with layers of history stacked in its endless levels. The Jedi Temple—later repurposed into the Imperial Palace—symbolizes the regime’s shift from guardianship to authoritarian control. Its prominence across the prequel era and Imperial rule cements its role as the political heart of the galaxy.