torturing her with a metal bar and then throwing her naked and bleeding onto the road. She died two weeks later.
Violent protests exploded in several cities after the Delhi gangrape, a reaction commentators and sociologists said reflected a deep well of frustration that many urban Indians feel over what they see as weak governance and poor leadership on social issues.
The government, seen as out of touch with the aspirations of the burgeoning urban middle class, was caught off guard by the protests.
The Delhi gangrape case led to the introduction of tougher rape laws in March, and for the first time open conversation about gender crime in television debates, social media and even Bollywood.
Still, sex crimes remain commonplace in India, and social commentators say patriarchal attitudes towards women have not been diluted by more than a decade of rapid economic growth.
Comments on social media websites and elsewhere ahead of the sentencing suggested that popular opinion favoured executing the men, although a survey by CNN-IBN-The Hindu newspaper in July showed Indians were divided on the merits of capital punishment.
Although the Supreme Court ruled in the 1980s that the death penalty should be imposed only in the "rarest of rare" cases, opponents say the reality is quite different.
Indian courts sentenced 1,455 prisoners to death between 2001 and 2011, according to the National Crime Records Bureau.
There are 477 people on death row. Many have been there for years. Human rights groups have been alarmed, however, by the vigour with which President Pranab Mukherjee, who took office in July 2012, has acted in clearing the backlog of clemency pleas. He has rejected 11, confirming the death penalty for 17 people.
Some women's rights groups and legal experts had opposed executing the Delhi attackers. Others have invoked the Gandhian principle that "an eye for an eye makes the whole world blind".
"Sending these four men to the gallows will accomplish nothing except short-term revenge," Tara Rao, director of Amnesty International India said in a statement.
"While the widespread anger over this Delhi gangrape case is understandable, authorities must avoid using the death penalty as a 'quick-fix' solution. There