Spiky strings in de Sitter space (original) (raw)

Physical Review D, 2003

We study both global as well as local (Nielsen-Olesen) strings in de Sitter space. While these type of topological defects have been studied in the background of a de Sitter metric previously, we study here the full set of coupled equations. We find only "closed" solutions. The behaviour of the metric tensor of these solutions resembles that of "supermassive" strings with a curvature singularity at the cosmological horizon. For global strings (and the composite defect) we are able to construct solutions which are regular on the interval from the origin to the cosmological horizon if the global string core lies completely inside the horizon.

Addendum to “Violating the string winding number maximally in anti–de Sitter space”

Physical review, 2017

We study n-string scattering amplitudes in three-dimensional Anti-de Sitter space (AdS 3). We focus our attention on the processes in which the winding number conservation is violated maximally; that is, those processes in which it is violated in n − 2 units. A worldsheet conformal field theory calculation leads us to confirm a previous conjecture about the functional form of these observables.

Exact integrability of strings inD-dimensional de Sitter spacetime

Physical Review D, 1993

We show the complete integrability of the string propagation in D-dimensional de Sitter spacetime. We find that the string equations of motion, which correspond to a noncompact O(D, 1)-symmetric o. model, plus the string constraints, are equivalent to a generalized sinh-Gordon equation. In D =2 this is the Liouville equation, in D = 3 this is the standard sinh-Gordon equation, and in D =4 this equation is related to the B2 Toda model. We show that the presence of instability is a general exact feature of strings in de Sitter space, as a direct consequence of the strong instability of the generalized sinh-Gordon Hamiltonian (which is unbounded from below), irrespective of any approximative scheme. We exhibit Backlund transformations for this generalized sinh-Gordon equation, which relate expanding and shrinking string solutions. We find all classical solutions in D =2 and physically analyze them. In D = 3 and D =4, we find the asymptotic behaviors of the solutions in the instability regime. The exact solutions exhibit asymptotically all the characteristic features of string instability: namely, the logarithmic dependence of the cosmic time u on the world sheet time v for u~+ 00, the stretching (or the shrinking) of the proper string size, and the proportionality between~and the conformal time.

Violating the string winding number maximally in anti–de Sitter space

Physical Review D, 2011

String scale thermal anti-de Sitter spaces

Journal of High Energy Physics

We study finite temperature string scale AdS3 backgrounds. One background is AdS3× S1× T2 in which the anti-de Sitter space-time and the circle are at the radius sqrtalphaprime\sqrt{\alpha^{\prime }}sqrtalphaprime α ′ . Using path integral techniques, we show that the bulk spectrum includes a continuum of states as well as Ramond-Ramond ground states that agree with those of the symmetric orbifold of the two-torus after second quantization. We also examine the one-loop free energy of the background AdS3× S1 at curvature radius sqrt2alphaprime/3\sqrt{2{\alpha}^{\prime }/3}sqrt2alphaprime/3 2 α ′ / 3 . In the space-time NSNS sector, the string theory spontaneously breaks conformal symmetry as well as R-charge conjugation symmetry. We prove that the minimum in the boundary energy is reached for a singly wound string. In the RR sector, we classify the infinite set of ground states with fractional R-charges. Moreover, we remark on the behaviour of critical temperatures as the curvature scale becomes smaller than the string scale.In an a...

p–q superstrings in anti-de-Sitter spacetime

Journal of Physics A: Mathematical and Theoretical, 2009

We study a field theoretical model for p-q-superstrings in a fixed Anti-de-Sitter background. We find that the presence of the negative cosmological constant tends to decrease the core radius of the strings. Moreover, the binding energy decreases with the increase of the absolute value of the cosmological constant. Studying the effect of the p-q-strings on Anti-de-Sitter space, we observe that the presence of the negative cosmological constant tends to decrease the deficit angle as compared to asymptotically flat space-time.

Quantizing strings in de Sitter space

Journal of High Energy Physics, 2007

We quantize a string in the de Sitter background, and we find that the mass spectrum is modified by a term which is quadratic in oscillating numbers, and also proportional to the square of the Hubble constant.

Strings and multi-strings in black hole and cosmological spacetimes

Arxiv preprint hep-th/9504007, 1995

Recent results on classical and quantum strings in a variety of black hole and cosmological spacetimes, in various dimensions, are presented. The curved backgrounds under consideration include the 2 + 1 black hole anti de Sitter spacetime and its dual, the black string, the ordinary D ≥ 4 black holes with or without a cosmological constant, the de Sitter and anti de Sitter spacetimes and static Robertson-Walker spacetimes. Exact solutions to the string equations of motion and constraints, representing circular strings, stationary open strings and dynamical straight strings, are obtained in these backgrounds and their physical properties (length, energy, pressure) are described. The existence of multi-string solutions, describing finitely or infinitely many strings, is shown to be a general feature of spacetimes with a positive or negative cosmological constant. Generic approximative solutions are obtained using the string perturbation series approach, and the question of the stability of the solutions is addressed. Furthermore, using a canonical quantization procedure, we find the string mass spectrum in de Sitter and anti de Sitter spacetimes. New features as compared to the string spectrum in flat Minkowski spacetime appear, for instance the fine-structure effect at all levels beyond the graviton in both de Sitter and anti de Sitter spacetimes, and the non-existence of a Hagedorn temperature in anti de Sitter spacetime. We discuss the physical implications of these results. Finally, we consider the effect of spatial curvature on the string dynamics in Robertson-Walker spacetimes.

hep-th/0612285 KIAS-P06067 Cosmic D- and DF-strings from D3¯D3: Black Strings and BPS Limit

2007

We study D- and DF-strings in a D3 ¯ D3 system in the context of Dirac-Born-Infeld type effective field theory. In the presence of an electric flux from a transverse direction, we discuss gravitating thick D-string solutions of a spatial manifold, S2 × R1, in which straight D-strings stretched along the R1 direction are attached to the south and north poles of the two-sphere. There is a horizon along its equator which means the structure of black strings is formed. We also discuss the BPS limits for thin parallel D- and DF-strings in both flat and curved spacetime. The BPS sum rule is obtained for arbitrarily-separated multi-string configuration with a Gaussian type tachyon potential. At the site of each thin BPS D(F)string, the pressure takes a finite value. We find that there exists maximum deficit angle π in the conical geometry induced by thin BPS D- and DF-strings. 1 1

String physics without strings: Regge trajectories, de Sitter space and hadron geometry

A new type of holografic principle is presented, which connects Quantum Chromo-dynamics (QCD) and de Sitter geometry with the old concept of hadronic "string". Some applications to hadronization and the origin of Regge trajectories are discussed. The involved global-local connection is explained in term of downward formal causality. (Chiatti), ignazio.licata@ejtp.info (Licata). 1 The term "R process" is used here as described by R. Penrose to indicate the localization, and generally the manifestation, of an elementary physical micro-event. The terminology is well known to physicists who deal with the foundations of quantum mechanics, but it is rather uncommon among particle physicists, a field where it should instead have a very natural citizenship, as we shall see.

Spiky strings in de Sitter space (original) (raw)

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