Andrew Yee[_1_]
February 28th 07, 05:01 PM
Communications Office
University of York
Heslington, U.K.
Media Information:
Professor Sam Braunstein
++44 (0)1904 434720; ++44 (0)7909 907397
27 February 2007
A hidden twist in the black hole information paradox
Professor Sam Braunstein, of the University of York's Department of Computer
Science, and Dr Arun Pati, of the Institute of Physics, Sainik School,
Bhubaneswar, India, have established that quantum information cannot be
'hidden' in conventional ways, or in Braunstein's words, "quantum
information can run but it can't hide."
This result gives a surprising new twist to one of the great mysteries about
black holes.
Conventional (classical) information can vanish in two ways, either by
moving to another place (e.g. across the internet), or by "hiding", such as
in a coded message. The famous Vernam cipher devised in 1917 or its relative
the one-time pad cryptographic code are examples of such classical
information hiding: the information resides neither in the encoded message
nor in the secret key pad used to decipher it -- but in correlations between
the two.
For decades, physicists believed that both these mechanisms were applicable
to quantum information as well, but Professor Braunstein and Dr Pati have
demonstrated that if quantum information disappears from one place, it must
have moved somewhere else.
In a paper published in the latest edition of Physical Review Letters,
Braunstein and Pati derive their 'no-hiding theorem' and use it to study
black holes which, in Einstein's Theory of Relativity, are characterized as
swallowing up anything that comes too close.
In the mid 1970s, Stephen Hawking showed that black holes eventually
evaporate away in a steady stream of featureless radiation containing no
information. But if a black hole has completely evaporated, where has the
information about it gone? This long standing question is known as the black
hole information paradox.
Now, Professor Braunstein and Dr Pati have ruled out the possibility that
information might escape from the black hole but be somehow hidden in
correlations between the Hawking radiation and the black hole's internal
state. Braunstein and Pati's result demonstrates that the black hole
information paradox is even more severe than previously believed.
Dr Pati said: "Our result shows that either quantum mechanics or Hawking's
analysis must break down, but it does not choose between these two
possibilities."
Professor Braunstein said: "The no-hiding theorem provides new insight into
the different laws governing classical and quantum information. It shows
that there's got to be new physics out there."
Notes to Editors:
"Quantum information cannot be completely hidden in correlations:
Implications for the black-hole information paradox" appears in the latest
Physical Review Letters.
Authors:
Samuel L. Braunstein
Professor of Quantum Computation, Department of Computer Science
University of York, York YO10 5DD, United Kingdom
Web: http://www.cs.york.ac.uk/~schmuel
and
Arun K. Pati
Institute of Physics, Sainik School Post
Bhubaneswar-751005, Orissa, India
++ 91 9861048134
University of York
Heslington, U.K.
Media Information:
Professor Sam Braunstein
++44 (0)1904 434720; ++44 (0)7909 907397
27 February 2007
A hidden twist in the black hole information paradox
Professor Sam Braunstein, of the University of York's Department of Computer
Science, and Dr Arun Pati, of the Institute of Physics, Sainik School,
Bhubaneswar, India, have established that quantum information cannot be
'hidden' in conventional ways, or in Braunstein's words, "quantum
information can run but it can't hide."
This result gives a surprising new twist to one of the great mysteries about
black holes.
Conventional (classical) information can vanish in two ways, either by
moving to another place (e.g. across the internet), or by "hiding", such as
in a coded message. The famous Vernam cipher devised in 1917 or its relative
the one-time pad cryptographic code are examples of such classical
information hiding: the information resides neither in the encoded message
nor in the secret key pad used to decipher it -- but in correlations between
the two.
For decades, physicists believed that both these mechanisms were applicable
to quantum information as well, but Professor Braunstein and Dr Pati have
demonstrated that if quantum information disappears from one place, it must
have moved somewhere else.
In a paper published in the latest edition of Physical Review Letters,
Braunstein and Pati derive their 'no-hiding theorem' and use it to study
black holes which, in Einstein's Theory of Relativity, are characterized as
swallowing up anything that comes too close.
In the mid 1970s, Stephen Hawking showed that black holes eventually
evaporate away in a steady stream of featureless radiation containing no
information. But if a black hole has completely evaporated, where has the
information about it gone? This long standing question is known as the black
hole information paradox.
Now, Professor Braunstein and Dr Pati have ruled out the possibility that
information might escape from the black hole but be somehow hidden in
correlations between the Hawking radiation and the black hole's internal
state. Braunstein and Pati's result demonstrates that the black hole
information paradox is even more severe than previously believed.
Dr Pati said: "Our result shows that either quantum mechanics or Hawking's
analysis must break down, but it does not choose between these two
possibilities."
Professor Braunstein said: "The no-hiding theorem provides new insight into
the different laws governing classical and quantum information. It shows
that there's got to be new physics out there."
Notes to Editors:
"Quantum information cannot be completely hidden in correlations:
Implications for the black-hole information paradox" appears in the latest
Physical Review Letters.
Authors:
Samuel L. Braunstein
Professor of Quantum Computation, Department of Computer Science
University of York, York YO10 5DD, United Kingdom
Web: http://www.cs.york.ac.uk/~schmuel
and
Arun K. Pati
Institute of Physics, Sainik School Post
Bhubaneswar-751005, Orissa, India
++ 91 9861048134