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23
Symmetry breaking and axionic strings in the warped deformed conifold
- JHEP 0409
"... We interpret D-strings at the bottom of the warped deformed conifold as axionic strings in the dual cascading SU(N + M) × SU(N) gauge theory. The axion is a massless pseudo-scalar glueball which we find in the supergravity fluctuation spectrum and interpret as the Goldstone boson of spontaneously b ..."
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Cited by 73 (10 self)
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We interpret D-strings at the bottom of the warped deformed conifold as axionic strings in the dual cascading SU(N + M) × SU(N) gauge theory. The axion is a massless pseudo-scalar glueball which we find in the supergravity fluctuation spectrum and interpret as the Goldstone boson of spontaneously broken U(1) baryon number symmetry. The existence of this massless glueball, anticipated in hep-th/0101013, supports the idea that the cascading gauge theory is on the baryonic branch, i.e. the U(1)B global symmetry is broken by expectation values of baryonic operators. We also find a massless scalar glueball, which is a superpartner of the pseudo-scalar. This scalar mode is a mixture of an NS-NS 2-form and a metric perturbation of the warped deformed conifold of a type first considered in hep-th/0012034.
The (p,q) String Tension in a Warped Deformed Conifold
, 2006
"... We find the tension spectrum of the bound states of p fundamental strings and q D-strings at the bottom of a warped deformed conifold. We show that it can be obtained from a D3-brane wrapping a 2-cycle that is stabilized by both electric and magnetic fluxes. Because the F-strings are ZM-charged wi ..."
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Cited by 25 (8 self)
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We find the tension spectrum of the bound states of p fundamental strings and q D-strings at the bottom of a warped deformed conifold. We show that it can be obtained from a D3-brane wrapping a 2-cycle that is stabilized by both electric and magnetic fluxes. Because the F-strings are ZM-charged with non-zero binding energy, binding can take place even if (p, q) are not coprime. Implications for cosmic strings are briefly discussed.
Spontaneous Creation of Inflationary Universes and the Cosmic Landscape
- JHEP 0409 (2004) 060, arXiv:hep-th/0406107; Saswat Sarangi, S.-H. Henry Tye, The Boundedness of Euclidean Gravity and the Wavefunction of the Universe, arXiv:hep-th/0505104; Saswat Sarangi, S.-H. Henry Tye, A Note on the Quantum Creation of Universes, arX
"... Abstract: We study some gravitational instanton solutions that offer a natural realization of the spontaneous creation of inflationary universes in the brane world context in string theory. Decoherence due to couplings of higher (perturbative) modes of the metric as well as matter fields modifies th ..."
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Cited by 10 (5 self)
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Abstract: We study some gravitational instanton solutions that offer a natural realization of the spontaneous creation of inflationary universes in the brane world context in string theory. Decoherence due to couplings of higher (perturbative) modes of the metric as well as matter fields modifies the Hartle-Hawking wavefunction for de Sitter space. Generalizing this new wavefunction to be used in string theory, we propose a principle in string theory that hopefully will lead us to the particular vacuum we live in, thus avoiding the anthropic principle. As an illustration of this idea, we give a phenomenological analysis of the probability of quantum tunneling to various stringy vacua. We find that the preferred tunneling is to an inflationary universe (like our early universe), not to a universe with a very small cosmological constant (i.e., like today’s universe) and not to a 10-dimensional uncompactified de Sitter universe. Such preferred solutions are interesting as they offer a cosmological mechanism for the stabilization of extra dimensions during the inflationary
FNAL-PUB-08-215-A-T Gravitational Wave Bursts from Cosmic Superstring Reconnections
, 901
"... We compute the gravitational waveform produced by cosmic superstring reconnections. This is done by first constructing the superstring reconnection trajectory, which closely resembles that of classical, instantaneous reconnection but with the singularities smoothed out due to the string path integra ..."
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Cited by 3 (0 self)
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We compute the gravitational waveform produced by cosmic superstring reconnections. This is done by first constructing the superstring reconnection trajectory, which closely resembles that of classical, instantaneous reconnection but with the singularities smoothed out due to the string path integral. We then evaluate the graviton vertex operator in this background to obtain the burst amplitude. The result is compared to the detection threshold for current and future gravitational wave detectors, finding that neither bursts nor the stochastic background would be detectable by Advanced LIGO. This disappointing but anticipated conclusion holds even for the most optimistic values of the reconnection probability and loop sizes. 1 1
A tutorial on links between cosmic string theory and superstring theory
"... Cosmic superstrings are introduced to non-experts. First D-branes and (p,q) strings are discussed. Then we explain how tachyon condensation in the early universe may have produced F, D and (p,q) strings. Warped geometries which can render horizon sized superstrings relatively light are discussed. Va ..."
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Cosmic superstrings are introduced to non-experts. First D-branes and (p,q) strings are discussed. Then we explain how tachyon condensation in the early universe may have produced F, D and (p,q) strings. Warped geometries which can render horizon sized superstrings relatively light are discussed. Various warped geometries including the deformed conifold in the Klebanov-Strassler geometry are reviewed and their warp factors are calculated. The decay rates for strings in the KS geometry are calculated and reasons for the necessity of orientifolds are reviewed. We then outline calculations of the intercommuting probability of F, D and (p,q) strings and explain in detail why cosmic superstring intercommuting probabilities can be small. We explore cosmic superstring networks. Their scaling properties are examined using the Velocity One Scale model and its extra dimensional extensions. Two different approaches and two sets of simulations are reviewed. Finally, we review in detail the gravitational wave amplitude calculations for strings with intercommuting probability
2007 Energy radiation by cosmic superstrings in brane inflation. [e-Print: arXiv:arXiv:0710.4609
"... The dominant method of energy loss by a loop of cosmic D-strings in models of warped brane inflation is studied. It is shown that the energy loss via Ramond-Ramond field radiation can dominate by many orders of magnitude over the energy radiation via gravitational wave emission. The ratio of these t ..."
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The dominant method of energy loss by a loop of cosmic D-strings in models of warped brane inflation is studied. It is shown that the energy loss via Ramond-Ramond field radiation can dominate by many orders of magnitude over the energy radiation via gravitational wave emission. The ratio of these two energy loss mechanisms depends on the energy scale of inflation, the mass scale of string theory and whether it is a single-throat or a multi-throat inflationary scenario. This can have important consequences for the detection of cosmic superstrings in the near future. It is argued that the bounds from CMB anisotropies and BBN are the dominant cosmological sources to constrain the physical parameters of the network of cosmic superstrings, whereas the role of the gravitational wave-based experiments may be secondary.
Cosmic String Lensing and Closed Time-like Curves
, 2008
"... In an analysis of the gravitational lensing by two relativistic cosmic strings, we argue that the formation of closed time-like curves proposed by Gott is unstable in the presence of particles (e.g. the cosmic microwave background radiation). Due to the attractor-like behavior of the closed time-lik ..."
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In an analysis of the gravitational lensing by two relativistic cosmic strings, we argue that the formation of closed time-like curves proposed by Gott is unstable in the presence of particles (e.g. the cosmic microwave background radiation). Due to the attractor-like behavior of the closed time-like curve, we argue that this instability is very generic. A single graviton or photon in the vicinity, no matter how soft, is sufficient to bend the strings and prevent the formation of closed time-like curves. We also show that the gravitational lensing due to a moving cosmic string is enhanced by its motion, not suppressed. 1
BPS limit of multi- D- and DF-strings in boundary string field theory,” arXiv:hep-th/0703144
"... A BPS limit is systematically derived for straight multi- D- and DF-strings from the D3 ¯ D3 system in the context of boundary superstring field theory. The BPS limit is obtained in the limit of thin D(F)-strings, where the Bogomolnyi equation supports singular static multi-D(F)-string solutions. Fo ..."
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Cited by 1 (1 self)
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A BPS limit is systematically derived for straight multi- D- and DF-strings from the D3 ¯ D3 system in the context of boundary superstring field theory. The BPS limit is obtained in the limit of thin D(F)-strings, where the Bogomolnyi equation supports singular static multi-D(F)-string solutions. For the BPS multi-string configurations with arbitrary separations, BPS sum rule is fulfilled under a Gaussian type tachyon potential and reproduces exactly the descent relation. For the DF-strings ((p,q)-strings), the distribution of fundamental string charge density coincides with its energy density and the Hamiltonian density takes the BPS formula of square-root form. 1 1
