Joseph Polchinski

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Joseph Polchinski, 2004

Joseph Gerard Polchinski (born May 16, 1954 in White Plains , New York ; † February 2, 2018 ) was an American theoretical physicist who mainly dealt with string theory.


Polchinski attended high school in Tucson until 1971 and then studied at Caltech in Pasadena , where he received his bachelor's degree (BS) in 1975. In 1980 he received his PhD from the University of California, Berkeley with Stanley Mandelstam . After postdoc positions at the Stanford accelerator SLAC 1980–82 and 1982 to 1984 at Harvard University , he was professor at the University of Texas at Austin from 1984 to 1992 . Since 1992 he was a professor at the University of California, Santa Barbara , where he was also a member of the Kavli Institute for Theoretical Physics .

Polchinski was best known for his introduction (1995) of the D-branes into string theory (higher-dimensional generalizations of strings with open strings ending on their surfaces). Previously, in 1986, with James Liu and James Hughes, he demonstrated the consistency of super-membrane theories. He also studied cosmological strings and AdS / CFT theory (which describes the equivalence of string theories in special manifolds with Yang-Mills theories on the edge of those manifolds) and wrote a two-volume textbook on string theory.

In 2012 he proposed a scenario of the fate of an observer falling into a black hole, which deviates from the predictions of the classical general theory of relativity (ART) by taking into account quantum effects. While according to the ART the observer would initially not notice any major changes when crossing the event horizon (a consequence of the equivalence principle), but would later be torn apart by tidal forces, Polchinski found the existence of a wall of fire (firewall) of extremely hot particles that would immediately burn the observer. The firewall was originally introduced as a solution to the entanglement paradoxes of Hawking radiation , but (since it contradicts the principle of equivalence) it is also understood as a "paradox" itself and led to a scientific discourse in the course of which Stephen Hawking, among others, spoke in 2014 about the concept of a strict one Event horizon in the GTR. According to Polchinski, the firewall paradox was an argument against the existence of the interior of black holes and arose from a "rocking" of the quantum entanglement in Hawking radiation. According to quantum mechanics, only two particles can be entangled at a time, but in Hawking radiation there are very many, which led Polchinski to the conclusion that it was reflected back from a wall of fire inside the black hole.

In 1985 he became a research fellow of the Alfred P. Sloan Foundation ( Sloan Research Fellow ). In 1997 he became a Fellow of the American Physical Society . In 2007 he received the Dannie Heineman Prize for Mathematical Physics and in 2008 the Dirac Medal (ICTP) . He was a member of the National Academy of Sciences from 2005 and of the American Academy of Arts and Sciences since 2002 . In 2013 and 2014 he received the Physics Frontiers Prize , for 2017 he was awarded the Breakthrough Prize in Fundamental Physics .

Polchinski died of a brain tumor in February 2018 .


  • With Jin Dai, Robert G. Leigh: New connections between string theories . In: Modern Physics Letters A , 4, 1989, p. 2073 (introduction to D-Branes).
  • What is string theory? Les Houches Lectures, 1994, arxiv : hep-th / 9411028 .
  • D-Branes and Ramond-Ramond-Charges . In: Physical Review Letters , 75, 1995, pp. 4724-4727.
  • TASI Lectures on D-Branes . 1996, arxiv : hep-th / 9611050 .
  • String theory. Cambridge University Press, Cambridge 1998.
  • Quantum gravity at the Planck length . SLAC, 1998, arxiv : hep-th / 9812104 .
  • With Gary T. Horowitz : Gauge-Gravity Duality . 2006, arxiv : gr-qc / 0602037 .
  • The Cosmological Constant and the String Landscape. Solvay Lectures 2006, arxiv : hep-th / 0603249 .
  • With Ahmed Almheiri, Donald Marolf, James Sully: Black Holes: Complementarity or Firewalls? In: J. High Energy Phys. , 2, 062, 2013, arxiv : 1207.3123 .
  • Joseph Polchinski: Memories of a Theoretical Physicist . arxiv : 1708.09093 .
  • Donald Marolf, Eva Silverstein: Joseph Gerard Polchinski Jr . In: Physics Today . tape 71 , no. 5 , May 2018, p. 66 , doi : 10.1063 / PT.3.3928 ( ).

Web links

Individual evidence

  1. Blog entry , accessed on February 3, 2018.
  2. Joseph Polchinski in the Mathematics Genealogy Project (English)Template: MathGenealogyProject / Maintenance / id used
  3. ^ Joseph Polchinski: Dirichlet Branes and Ramond-Ramond Charges. In: Physical Review Letters. 75, 1995, pp. 4724-4727.
  4. James Hughes, Jun Liu, Joseph Polchinski: Supermembranes. In: Physics Letters. B 180, 1986, pp. 370-374.
  5. Ahmed Almheiri, Donald Marolf, Joseph Polchinski, James Sully: Black Holes: Complementarity or Firewalls? In: Journal of High Energy Physics , 2013, arxiv : 1207.3123
  6. Zeeya Merali: Fire in the hole! In: Nature , News Feature. April 5, 2013.
  7. KC Cole: Wormholes Untangle a Black Hole Paradox . In: Quanta Magazine. April 24, 2015. According to this, not only the particle-antiparticle pairs that cause the Hawking radiation are entangled, but these with other particles / antiparticles. However, only two particles / antiparticles can be entangled, which, according to Polchinski and colleagues, suggests a singular behavior of space-time, the wall of fire.
  8. Joseph Polchinski. In: Fundamental Physics Breakthrough Prize: Laureates. Retrieved on October 31, 2018 (from the laudation: " For transformative advances in quantum field theory, string theory, and quantum gravity. ").