The Batman dies and returns as the Sun sets and rises. Along with other solar deities, like Apollo, Ra, Baldur, Hyperion, Legba, or Christ, he can be associated with rebirth, harmony, compassion, masculinity, and beauty. The Sun is the realm of the higher ego: Mathers' Holy Guardian Angel. The God-in-Man. Resurrection is a chief function, a condition fulfilled in Morrison's Batman R.I.P. and The Return of Bruce Wayne. Sun gods are also gods of balance and equilibrium. Christ speaks in terms of balance: "Blessed are the poor in spirit, for theirs is the kingdom of heaven. Blessed are those who mourn, for they will be comforted. Blessed are the meek, for they will inherit the earth." (Matt 5:3-5) Weights and pulleys illustrate the universe's occupation with this idea.
In the Bat myth, we find The Batman acting as a balancing mechanism for every other personality in Gotham. When he is with the Venusian Dick Grayson, he manifests his cold, unfeeling side. With the wise and fatherly Alfred Pennyworth, he becomes the tantrum-throwing child. In the presence of the Joker's chaos, he is order.
Most scientific types believe that the Sun is the center of our solar system (http://curious.astro.cornell.edu/question.php?number=481), holding the planets in orbit with its gravitational pull. The metaphorical connection should be obvious. The Batman can have his name on the cover, and only show up for a few pages, like in Batman: Room Full of Strangers (Morse, 2004), or Batman: Devil's Asylum (Grant, Stelfreeze,1995).
He can be read as the heart of Gotham, the hub that all others revolve around. In kabbalah, the sephirah associated with the Sun is called Tiphareth, which means "beauty". Tiphareth is tied to the sixes of the Tarot: Success, Science, Pleasure, Victory. It is also connected to the heart.
In Scorsese's Last Temptation of Christ, Jesus says, "If I was a woodcutter, I'd cut. If I was a fire, I'd burn. But I'm a heart and I love. That's the only thing I can do."