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Accelerating branes and the string / black hole transition
"... String theory in Euclidean flat space with a spacelike linear dilaton contains a D1brane which looks like a semiinfinite hairpin. In addition to its curved shape, this “hairpin brane ” has a condensate of the open string tachyon stretched between its two sides. The tachyon smears the brane and shi ..."
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Cited by 28 (5 self)
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String theory in Euclidean flat space with a spacelike linear dilaton contains a D1brane which looks like a semiinfinite hairpin. In addition to its curved shape, this “hairpin brane ” has a condensate of the open string tachyon stretched between its two sides. The tachyon smears the brane and shifts the location of its tip. The Minkowski continuation of the hairpin brane describes a D0brane freely falling in a linear dilaton background. Effects that in Euclidean space are attributed to the tachyon condensate, give rise in the Minkowski case to a stringy smearing of the trajectory of the Dbrane by an amount that grows as its acceleration increases. When the Unruh temperature of the brane reaches the Hagedorn temperature of perturbative string theory in the throat, the rolling Dbrane state becomes nonnormalizable. We propose that black holes in string theory exhibit similar properties. The Euclidean black hole solution has a condensate of a tachyon winding around Euclidean time. The Minkowski manifestation of this condensate is a smearing of the geometry in a layer around the horizon. As the Hawking temperature, Tbh, increases, the width of this layer grows. When Tbh reaches the Hagedorn temperature, the size of this “smeared horizon ” diverges, and the black hole becomes nonnormalizable. This provides
Fundamental strings and black holes
 JHEP
, 2007
"... We propose a black hole thermodynamic description of highly excited charged and uncharged perturbative string states in 3 + 1 dimensional type II and 4 + 1 dimensional heterotic string theory. We also discuss the generalization to extremal and nonextremal black holes carrying magnetic charges. 11/0 ..."
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Cited by 15 (1 self)
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We propose a black hole thermodynamic description of highly excited charged and uncharged perturbative string states in 3 + 1 dimensional type II and 4 + 1 dimensional heterotic string theory. We also discuss the generalization to extremal and nonextremal black holes carrying magnetic charges. 11/06
Fundamental Strings and Higher Derivative Corrections to d–Dimensional
 Black Holes, JHEP 1002 (2010) 012 [arXiv:0909.5264 [hepth
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Rolling Tachyon in Antide Sitter Spacetime
, 2006
"... We study the decay of the unstable Dparticle in threedimensional antide Sitter spacetime using worldsheet boundary conformal field theory methods. We test the open string completeness conjecture in a background for which the phase space available is only fieldtheoretic. This could present a ser ..."
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We study the decay of the unstable Dparticle in threedimensional antide Sitter spacetime using worldsheet boundary conformal field theory methods. We test the open string completeness conjecture in a background for which the phase space available is only fieldtheoretic. This could present a serious challenge to the claim. We compute the emission of closed strings in the AdS3 × S3 × T4 background from the knowledge of the exact corresponding boundary state we construct. We show that the energy stored in the brane is mainly converted into very excited long strings. The energy stored in short strings and in open string pair production is much smaller and finite for any value of the string coupling. We find no ”missing energy ” problem. We compare our results to those obtained for a decay in flat spacetime and to a background in the presence of a linear dilaton. Some remarks on holographic aspects of the problem are made. 1 Introduction and summary Understanding the physics of timedependent backgrounds is one of the the greatest challenges in string theory. It is important for the understanding of basic issues in quantum gravity and for
Hagedorn Strings and Correspondence Principle in AdS3
, 705
"... Motivated by the possibility of formulating a strings/black hole correspondence in AdS space, we extract the Hagedorn behavior of thermal AdS3 bosonic string from 1loop partition function of SL(2, R) WZW model. We find that the Hagedorn temperature is monotonically increasing as the AdS radius shri ..."
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Motivated by the possibility of formulating a strings/black hole correspondence in AdS space, we extract the Hagedorn behavior of thermal AdS3 bosonic string from 1loop partition function of SL(2, R) WZW model. We find that the Hagedorn temperature is monotonically increasing as the AdS radius shrinks, reaches a maximum of order of string scale set by the unitarity bound of the CFT for internal space. The resulting density of states near the Hagedorn temperature resembles the form as for strings in flat space and is dominated by the spacelike long string configurations. We then argue a conjectured strings/black hole correspondence in AdS space by applying the Hagedorn thermodynamics. We find the size of the corresponding black hole is a function of the AdS radius. For large AdS radius a black hole far bigger than the string scale will form. On the contrary, when the AdS and string scales are comparable a string size black hole will form. We also examine strings on BTZ background obtained through SL(2, Z) transformation. We find a tachyonic divergence for a BTZ black hole of string scale size.
STRING THEORY AT THE TIP OF THE CIGAR
"... In arXiv:1208.3930 we argued that string theory at the tip of the cigar geometry, obtained by a Wick rotation of the Schwarzschild background, exhibits unexpected features that include degrees of freedom that are confined to the tip. Using the exact worldsheet description of near extremal NS5branes ..."
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In arXiv:1208.3930 we argued that string theory at the tip of the cigar geometry, obtained by a Wick rotation of the Schwarzschild background, exhibits unexpected features that include degrees of freedom that are confined to the tip. Using the exact worldsheet description of near extremal NS5branes we further study string theory at the tip of the cigar and find more evidence to its surprising properties. 1 ar
Deconstructing the Little Hagedorn Holography
, 2007
"... We study aspects of the thermodynamics of Little String Theory, using its geometrical definition in critical tendimensional string theory. We find that bulk radiation effects tend to screen the Hagedorn behaviour of the theory, in contrast to the behaviour in the AdS system background. The resultin ..."
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We study aspects of the thermodynamics of Little String Theory, using its geometrical definition in critical tendimensional string theory. We find that bulk radiation effects tend to screen the Hagedorn behaviour of the theory, in contrast to the behaviour in the AdS system background. The resulting density of states of the system, when stable, is described by a sevendimensional nonrelativistic gas. This requires modifications of the holographic Little Hagedorn picture. Using deconstructions we suggest such modifications. The model is embedded into a system which has an ultraviolet fixed point with an AdS description. We investigate the thermodynamical properties of these UV completed models. It is found that the Hagedorn regime survives in a finite band of superheated states that eventually decay into the plasma phase of the conformal field theory that serves as UV regulator. This is manifested in a firstorder phase transition that is driven by radiative corrections.
hepth/0510211 The Charged Black Hole/String Transition
, 2005
"... We generalize the discussion of [1] to charged black holes. For the two dimensional charged black hole, which is described by an exactly solvable worldsheet theory, a transition from the black hole to the string phase occurs when the Hawking temperature of the black hole reaches a limiting value, th ..."
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We generalize the discussion of [1] to charged black holes. For the two dimensional charged black hole, which is described by an exactly solvable worldsheet theory, a transition from the black hole to the string phase occurs when the Hawking temperature of the black hole reaches a limiting value, the temperature of free strings with the same mass and charge. At this point a tachyon winding around Euclidean time in the Euclidean black hole geometry, which has a nonzero condensate, becomes massless at infinity, and the horizon of the black hole is infinitely smeared. For ReissnerNordstrom black holes in d ≥ 4 dimensions, the exact worldsheet CFT is not known, but we propose that it has similar properties. We check that the leading order solution is in good agreement with this In [1] a new picture of the string/black hole transition (see [25] for earlier discussions) was proposed. According to this picture, as the Hawking temperature of a black hole Tbh increases, the geometry develops large fluctuations in a wider and wider region around the horizon. When Tbh approaches the temperature of fundamental strings with the same
Fundamental Strings and Higher Derivative
, 909
"... Abstract: We study aspects of ddimensional black holes with two electric charges, corresponding to fundamental strings with generic momentum and winding on an internal circle. The perturbative α ′ corrections to such black holes and their gravitational thermodynamics are obtained. The latter are de ..."
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Abstract: We study aspects of ddimensional black holes with two electric charges, corresponding to fundamental strings with generic momentum and winding on an internal circle. The perturbative α ′ corrections to such black holes and their gravitational thermodynamics are obtained. The latter are derived using the Euclidean approach and the Wald formula for the entropy. We find that the entropy and the charge/mass ratio of black holes increase in α ′ for any mass and charges, and in all dimensions. Contents