We review the features of the pomeron in the S-matrix theory and in quantum field theory. We extend those general properties to the pomeron of closed bosonic string theory in a Minkowskian background. We compute the couplings of the pomeron to the lowest mass levels of closed bosonic string states in flat space. We recognize the deviation from the linearity of the Regge trajectories in a five dimensional anti De Sitter background.
We derive pomeron vertex operators for bosonic strings and superstrings in the presence of D-branes. We demonstrate how they can be used in order to compute the Regge behavior of string amplitudes on D-branes and the amplitude of ultrarelativistic D-brane scattering. After a lightning review of the BCFW method, we proceed in a classification of the various BCFW shifts possible in a field/string theory in the presence of defects/D-branes. The BCFW shifts present several novel features, such as the possibility of performing single particle momentum shifts, due to the breaking of momentum conserv…
We identify classical string solutions which directly give the classical part of the strong coupling pomeron intercept. The relevant solution is a close cousin of the GKP folded string, which is not surprising given the known relation with twist-2 operators. Our methods are applicable, however, also for nonzero conformal spin where we do not have a clear link with anomalous dimensions of a concrete class of operators. We analyze the BFKL folded string from the algebraic curve perspective and investigate its possible particle content.
Using the recent solution of the triple Pomeron coupling in the QCD dipole picture as a closed string amplitude with six legs, its analytical form in terms of hypergeometric functions and numerical value are derived.
We model the soft pomeron in QCD using a scalar Polyakov string with extrinsic curvature in the bottom-up approach of holographic QCD. The overall dipole-dipole scattering amplitude in the soft pomeron kinematics is shown to be sensitive to the extrinsic curvature of the string for finite momentum transfer. The characteristics of the diffractive peak in the differential elastic $pp$ scattering are affected by a small extrinsic curvature of the string.
We develop a formalism where the hard and soft pomeron contributions to high energy scattering arise as leading Regge poles of a single kernel in holographic QCD. The kernel is obtained using effective field theory inspired by Regge theory of a 5-d string theory. It describes the exchange of higher spin fields in the graviton Regge trajectory that are dual to glueball states of twist two. For a specific holographic QCD model we describe Deep Inelastic Scattering in the Regge limit of low Bjorken x, finding good agreement with experimental data from HERA. The observed rise of the effective pome…
We consider contributions of the open-string singlet~(OSS) interaction to the proton-proton scattering. Modelling baryon and meson as instanton and open string in the effective QCD string model, the typical pomeron is identified with a massive spin-2 closed string. According to the open-closed string duality, the massive spin-2 closed string is accompanied by the open-string singlet interaction with universal coupling. The flat space 4-point open-string singlet amplitudes and cross sections are computed in the Regge limit. Including both the open and closed string pomerons, we fit the differen…
The traditional description of high-energy small-angle scattering in QCD has two components -- a soft Pomeron Regge pole for the tensor glueball, and a hard BFKL Pomeron in leading order at weak coupling. On the basis of gauge/string duality, we present a coherent treatment of the Pomeron. In large-N QCD-like theories, we use curved-space string-theory to describe simultaneously both the BFKL regime and the classic Regge regime. The problem reduces to finding the spectrum of a single j-plane Schrodinger operator. For ultraviolet-conformal theories, the spectrum exhibits a set of Regge trajecto…
The spectrum of light baryons and mesons has been reproduced recently by Brodsky and Teramond from a holographic dual to QCD inspired in the AdS/CFT correspondence. They associate fluctuations about the AdS geometry with four dimensional angular momenta of the dual QCD states. We use a similar approach to estimate masses of glueball states with different spins and their excitations. We consider Dirichlet and Neumann boundary conditions and find approximate linear Regge trajectories for these glueballs. In particular the Neumann case is consistent with the Pomeron trajectory.
We suggest that the perturbative and non-perturbative descriptions of the Pomeron can be viewed as complementary descriptions of different phases in the Pomeron phase diagram, with a phase boundary where the proper description of the produced systems are "string balls". Their intrinsic entropy is calculated and turned out to be the same, as the recently reported perturbative entanglement entropy. The distribution of large multiplicities stemming from the string balls is also wide, with its moments close to those reported for hadrons in $pp$ collisions at the LHC. At low-x, the quantum string i…
We study high energy scattering amplitudes in a strongly coupled (confining) gauge theory using the AdS/CFT correspondence. The scattering described by a Wilson line/loop correlation function was shown earlier to correspond to minimal surfaces of the helicoid type, and gave amplitudes with unit intercept and linear trajectory. In this paper we find the correction to the intercept from quadratic fluctuations of the string worldsheet around the helicoid. The relevant term comes from analytical continuation of a Lüscher like term. It is coupling-constant independent and proportional to the number…
It has recently been shown that the ordinary bosonic string can be represented by a special background of N=1 or N=2 strings. In this paper, it will be shown that the bosonic string can also be represented by a special background of $W$-strings.
In the past decade overwhelming evidence has emerged for a conjectured duality between a wide class of gauge theories in d dimensions and string theories on asymptotically AdS_{d+1} spaces. We apply this duality to scattering processes that occur via Pomeron exchange. First we develop the Pomeron in string theory, as done by Brower, Polchinski, Strassler and Tan, showing that it naturally emerges as the Regge Trajectory of the AdS graviton. Next we apply the AdS Pomeron to the study of Deeply Virtual Compton Scattering (DVCS), and see that our model gives good results when compared to HERA dat…
A formal relationship between scattering amplitudes in critical bosonic string theory and correlation functions of operators in topological string theory is found.
Holographic AdS/QCD models of the Pomeron unite a string-based description of hadronic reactions of the pre-QCD era with the perturbative BFKL approach. The specific version we will use due to Stoffers and Zahed, is based on a semiclassical quantization of a "tube" (closed string exchange or open string virtual pair production) in its Euclidean formulation using the scalar Polyakov action. This model has a number of phenomenologically successful results. The periodicity of a coordinate around the tube allows the introduction of a Matsubara time and therefore an effective temperature Teff on th…
In order to investigate to what extent string theories are different vacua of a general string theory (the ``universal string"), we discuss realizations of the bosonic string as particular background of certain types of $W$-strings. Our discussions include linearized $W_3^{lin}$, non-critical $W_3$, linearized $W_3^{(2)lin}$ and critical $W_3^{(2)}$ realizations of the bosonic string.
The results conjectured here are based on tachyon condensation in compactified bosonic strings. They can in fact be proven from compactification alone, but this step was not treated consistently here. The proof is given in a new version of the paper: hep-th/0106235
We re-examine a string dual model for elastic proton-proton scattering via Pomeron exchange. We argue that the method of "Reggeizing" a propagator to take into account an entire trajectory of exchanged particles can be generalized, in particular by modifying the value of the mass-shell parameter in the model. We then fit the generalized model to scattering data at large s and small t. The fitting results are inconclusive, but suggest that a better fit might be obtained by allowing the mass-shell to vary. The model fits the data equally well (roughly) for a wide range of values of the mass-shel…
I construct a complete 1-loop partition function of a bosonic closed string on orbifolds. Furthermore, I derive sufficient conditions for the modular invariance of the partition function.
We review some exact solitonic solutions of string theory with higher-membrane structure. These include an axionic instanton solution of bosonic string theory as well as multi-instanton and multimonopole solutions of heterotic string theory. The heterotic solutions reveal some interesting aspects of string theory as a theory of quantum gravity.
Recently Berkovits and Vafa have shown that the bosonic string can be viewed as the fermionic string propagating in a particular background. Such a background is described by a somewhat unusual $N=1$ superconformal system. By coupling it to $N=1$ supergravity I construct a local supersymmetric action for the bosonic string.
Exploiting the strict analogy between the motion of strings and extended-like spinning particles, we propose an original kinematical formulation of the spin of bosonic strings and give, for the first time, an analytical derivation of an explicit expression of the string spin vector.
The thermofield dynamics of the D=26 closed bosonic thermal string theory is described in proper reference to the thermal duality symmetry as well as the thermal stability of modular invariance in association with the global phase structure of the bosonic thermal string ensemble.
In this paper we consider tree-level scattering in the minimal N=4 topological string and show that a large class of N-point functions can be recast in terms of corresponding amplitudes in the (1,k) minimal bosonic string. This suggests a non-trivial relation between the minimal N=4 topological strings, the (1,k) minimal bosonic strings and their corresponding ADE matrix models. This relation has interesting and far-reaching implications for the topological sector of six-dimensional Little String Theories.
The topological presentation of pomeron exchange at the proton-proton collision of high energy is cylinder that is covered with the net of quark-gluon exchanges. I suggest that the process of double diffraction dissociation (DD) can be presented as one pomeron exchange with the central loop of two uncut pomeron cylinders. Taking into account that the junction of three gluon strings (SJ) has the positive baryon number, as well as the antijunction is of negative baryon charge, our neutral pomeron torus can be covered with only a certain number of hexagons that are built of 3 junction and 3 antij…
In this paper we would like to discuss the emergence of D-branes from infinite many D-instantons in bosonic and type IIA string theory in the framework of boundary string field theory.
In this paper we present two solutions of open bosonic string field theory defined on D0-brane background that correspond to the change of the D0-brane position in the transverse space.
We briefly review the approach to dipole-dipole scattering in holographic QCD developed in ARXIV:1202.0831. The Pomeron is modeled by exchanging closed strings between the dipoles and yields Regge behavior for the elastic amplitude. We calculate curvature corrections to this amplitude in both a conformal and confining background, identifying the holographic direction with the virtuality of the dipoles. The it wee-dipole density is related to the string tachyon diffusion in both virtuality and the transverse directions. We give an explicit derivation of the dipole saturation momentum both in th…
We present example of exact solution to Witten's open bosonic string field theory. We will analyse the new BRST operator and we will argue that the new solution describes the flow from zero slope limit to the tensionless limit in the string world-sheet action.
We refine the relation between the renormalized partition function of the open bosonic string in background fields and the effective action. In the process, we get some leading derivative corrections to the Born-Infeld action which include all powers of the gauge field.
Deser-Zumino supergravity action for the graviton and gravitino pair, in four dimensions is deduced from the Nambu-Goto string action of the 26 dimension using the Principle of Equivalence.
We consider the possibility of a bosonic (meta)stabilization of a cosmic gauge string loop due to the presence of a gas of low mass bosonic particles which become trapped within the string core. This boson gas exerts a pressure which tends to counteract the string tension, allowing a circular string loop to find a finite equilibrium radius, provided that gas particles do not escape the string core. However, high energy bosons do escape, and consequently the loop shrinks and the temperature rises. Estimates indicate that the bosonic stabilization mechanism is ineffective, and the loop is unstab…
In a previous paper we showed that bracket relations uniquely fix the tree-level bosonic string $S$-matrix for $N\leq 26$ particle scattering. In this note we extend the proof to $N$-particle scattering for all $N$.
Conventional superstring amplitudes in flat space exhibits exponential fall off at wide angle in contrast to the power law behavior found in QCD. It has recently been argued by Polchinski and Strassler that this conflict can be resolved via String/Gauge duality. They carried out their analysis in terms of strings in a deformed $AdS^5$ background. On the other hand, an equally valid approach to the String/Gauge duality for 4-d QCD is based on M-theory in a specific Black Hole deformation of $AdS^7 \times S^4$. We show that a very natural extension to this phenomenologically interesting M-theory…
We show that the bosonic string theory quantized in the Beltrami parametrization possesses a supersymmetric structure like the vector-supersymmetry already observed in topological field theories.
We study the worldsheet theory of bosonic string from the point of view of the BV formalism. We explicitly describe the derived Poisson structure which arizes when we expand the Master Action near a Lagrangian submanifold. The BV formalism allows us to clarify the mechanism of holomorphic factorization of string amplitudes.
We elucidate the properties of a gas of free closed bosonic strings in thermal equilibrium. Our starting point is the intensive generating functional of connected one-loop closed vacuum string graphs given by the Polyakov path integral. Invariance of the path integral under modular transformations gives a thermal duality invariant expression for the free energy of free closed strings at finite temperature. The free bosonic string gas exhibits a self-dual Kosterlitz-Thouless phase transition. The thermodynamic potentials of the gas of free bosonic closed strings are shown to exhibit an infinite…
We discuss tachyon configuration for the unoriented bosonic string theory which produces a bosonic string theory with SO(32) gauge symmetry in ten dimensions. It is closely related to the tachyon condensation scenario proposed by A. Sen. We also give the boundary state description of the tachyon condensation process, with some emphasis on the rôle of orbifold conformal field theory.
Two-dimensional fermionic string theory is shown to have a structure of topological model, which is isomorphic to a tensor product of two topological ghost systems independent of each other. One of them is identified with $c=1$ bosonic string theory while the other has trivial physical contents. This fact enables us to regard two-dimensional fermionic string theory as an embedding of $c=1$ bosonic string theory in the moduli space of fermionic string theories. Upon this embedding, the discrete states of $c=1$ string theory are mapped to those of fermionic string theory, which is considered to …
This short note is devoted to the study of the integrability of the bosonic string on AdS(5)xS(5) in the uniform light-cone gauge. We construct Lax connection for gauge fixed theory and we argue that it is flat.
We show that Witten's two-dimensional string black hole metric is exactly conformally invariant in the supersymmetric case. We also demonstrate that this metric, together with a recently proposed exact metric for the bosonic case, are respectively consistent with the supersymmetric and bosonic $σ$-model conformal invariance conditions up to four-loop order.
Deformation quantization of bosonic strings is considered. We show that the light-cone gauge is the most convenient classical description to perform the quantization of bosonic strings in the deformation quantization formalism. Similar to the field theory case, the oscillator variables greatly facilitates the analysis. The mass spectrum, propagators and the Virasoro algebra are finally described within this deformation quantization scheme.
In this work we will investigate how the non-commutativity arises into the string theory, \textit{i.e.}, how the bosonic string theory attaches to a D3-brane in the presence of magnetic fields. In order to accomplish the proposal, we departure from the commutative two-dimensional harmonic oscillator, which after the application of the general Bopp's shifts Matrix Method, the non-commutative version of the two-dimensional harmonic oscillator is obtained. After that, this non-commutative harmonic oscillator will be mapped into the bosonic string theory in the light cone frame, which it now appea…
We consider a prescription for introducing deformed dispersion relations in the bosonic string action. We find that in a subset of such theories it remains true that the embedding coordinates propagate linearly on the worldsheet. While both the string modes and the center of mass propagate with deformed dispersion relations, the speed of light remains energy independent. We consider the canonical quantization of these strings, and find that it is possible to choose theories so that ghost modes still decouple, as usual. However the Virasoro algebra now exhibits an energy dependent central charg…
We assume that the total target phase space is non-commutative. This leads to the generalization of the oscillator-algebra of the string, and the corresponding Virasoso algebra. The effects of this non-commutativity on some string states will be studied.
The potential of the closed bosonic bulk tachyon is investigated using $\mathcal{N}~=~1$ closed superstring field theory formulated around Berkovits' and Vafas embedding of the bosonic string into the superstring. From this point of view the bosonic minimum gets destabilized by new deformations of the underlying CFT. Another critical point of the potential is identified by solving the equation of motions and the properties of this new solution are discussed.
In the cubic string field theory, using the gauge invariant operators corresponding to the on-shell closed string vertex operators, we have explicitly evaluated the decay amplitudes of two open string tachyons or gauge fields to one closed string tachyon or graviton up to level two. We then evaluated the same amplitudes in the bosonic string theory, and shown that the amplitudes in both theories have exactly the same pole structure. We have also expanded the decay amplitudes in the bosonic string theory around the Mandelstam variable s=0, and shown that their leading contact terms are fully co…
A bosonic string coupled to the generalized Chern-Simons theory in 3+1D acquires a magnetic field along itself, when it is closed, and a topological charge at its extremity, when it is open. We construct the creation operators for the full quantum field states associated to these strings and determine the dual algebra satisfied by them. We show that the creation operator fo the composite state of a quantum closed bosonic string, bearing a magnetic flux, and a topologically charged open bosonic string, possesses generalized statistics. The relation of our results with previous approaches to the…
We review the emergence of the ten-dimensional fermionic closed string theories from subspaces of the Hilbert space of the 26-dimensional bosonic closed string theory compactified on an $E_8\times SO(16)$ lattice. They arise from a consistent truncation procedure which generates space-time fermions out of bosons. This procedure is extended to open string sectors. We prove that truncation of the unique tadpole-free $SO(2^{13})$ bosonic string theory compactified on the above lattice determines the anomaly free Chan-Paton group of the Type I theory and the consistent Chan-Paton groups of Type O …
In a recent work it has been shown that the bosonic strings could be embedded into a special class of $N=1$ fermionic strings. We argue that the superpartners of any physical state in the spectrum of this fermionic string is non-physical. So, there is no supersymmetry in the space of physical states and the embedding is, in this sense, ``trivial''. We here propose two different constructions as possible candidates of non-trivial embeddings of the non-critical bosonic strings into some special class of $N=1$ fermionic strings of which one is the non-critical NSR string. The BRST charge of the $…
We argue that the higher space-time derivative terms that occur in closed bosonic string field theory are reminiscent of those found in the Landau theory of liquid-crystal transitions. We examine the lowest level approximation of the closed bosonic string and find evidence for the existence of a new vacuum that spontaneously breaks Lorentz and translation symmetries. This effect can be interpreted as a spontaneous compactification of the theory.
We review the emergence of the ten-dimensional fermionic closed string theories from subspaces of the Hilbert space of the 26-dimensional bosonic closed string theory compactified on an $E_8\times SO(16)$ lattice. They arise from a consistent truncation procedure which generates space-time fermions out of bosons. This procedure is extended to open string sectors. We prove, from bosonic considerations alone, that truncation of the unique tadpole-free $SO(2^{13})$ bosonic string theory compactified on the above lattice determines the anomaly free Chan-Paton group of the Type I theory. It also yi…
A new family of non critical bosonic string backgrounds in arbitrary space time dimension $D$ and with $ISO(1,D-2)$ Poincaré invariance are presented. The metric warping factor and dilaton agree asymptotically with the linear dilaton background. The closed string tachyon equation of motion enjoys, in the linear approximation, an exact solution of ``kink'' type interpolating between different expectation values. A renormalization group flow interpretation ,based on a closed string tachyon potential of type $-T^{2}e^{-T}$, is suggested.
We obtain the effective action for the bosonic string with arbitrary Yang-Mills fields, up to the α' order, in general dimensions. The form of the action is determined by the requirement that the action admit well-defined Killing spinor equations, whose projected integrability conditions give rise to the full set of equations of motion. The success of the construction suggests that the hidden "pseudo-supersymmetry" associated with the Killing spinor equations may be a property of the bosonic string itself.
We propose the action for the nonrelativistic string invariant under general coordinate transformations on the string worldsheet. The Hamiltonian formulation for the nonrelativistic string is given. Particular solutions of the Euler-Lagrange equations are found in the time gauge.
We study soliton gauge states in the spectrum of bosonic string compatified on torus. The enhenced Kac-Moody gauge symmetry, and thus T-duality, is shown to be related to the existence of these soliton gauge states in some moduli points.
