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In these notes we review the calculation of Jones polynomials using a matrix representation of the braid group and Temperley-Lieb algebra. The pseudounitary representation that we consider allows constructing ``states'' from the group/algebra matrices and compute the knot invariants as matrix elements, rather than traces. In comparison with a more standard way of computing the invariants through traces, the matrix element method is more interesting and complete from the point of view of applications. As a byproduct of the discussion we prove a general formula for pretzel knots., Comment: lecture notes, 9 pages, some typos fixed and some references added in this version

We use the topological quantum field theory description of states in Chern-Simons theory to discuss the relation between spacetime connectivity and entanglement, exploring the paradigm entanglement=topology. We define a special class of states in Chern-Simons with properties similar to those of holographic states. While the holographic states are dual to classical geometries, these connectome states represent classical topologies, which satisfy a discrete analog of the Ryu-Takayanagi formula and characteristic inequalities for the entanglement entropy. Generic states are linear combinations of connectomes, and the theory also has nonperturbative states which are global spacetime defects formed by a large number of quantum fluctuations. Topological presentation of quantum states and emergence of topology from entanglement may be useful for building a generalization to geomentry, that is quantum gravity. Thinking of further quantum gravity comparisons we discuss replica wormholes and conclude that similar objects exist beyond gravitational theories. The topological theory perspective suggests that the sum over all wormholes is always factorizable, even though the individual ones might not be., Comment: 22 pages, 3 figures

Topological quantum field theories (TQFT) encode properties of quantum states in the topological features of abstract manifolds. One can use the topological avatars of quantum states to develop intuition about different concepts and phenomena of quantum mechanics. In this paper we focus on the class of simplest topologies provided by a specific TQFT and investigate what the corresponding states teach us about entanglement. These ``planar connectome" states are defined by graphs of simplest topology for a given adjacency matrix. In the case of bipartite systems the connectomes classify different types of entanglement matching the classification of stochastic local operations and classical communication (SLOCC). The topological realization makes explicit the nature of entanglement as a resource and makes apparent a number of its properties, including monogamy and characteristic inequalities for the entanglement entropy. It also provides tools and hints to engineer new measures of entanglement and other applications. Here the approach is used to construct purely topological versions of the dense coding and quantum teleportation protocols, giving diagrammatic interpretation of the role of entanglement in quantum computation and communication. Finally, the topological concepts of entanglement and quantum teleportation are employed in a simple model of information retrieval from a causally disconnected region, similar to the interior of an evaporating black hole., Comment: 28 pages, 7 figures

There has been considerable recent interest in type II string compactifications on AdS$_3\times$S$^3\times$M$_{4}$ due to both new progress in the AdS$_3$/CFT$_2$ correspondence and an independent search for new ${\cal N}=(4,0)$ supergravity solutions. In this work we report a new family of small ${\cal N}=(4,0)$ preserving warped AdS$_3\times$S$^3\times $CY$_2$ compactifications of type IIB supergravity. The S$^3$ in this family is non trivially fibered over the CY$_2$. We show how these new solutions provide a IIB embedding of minimal ungauged $d=5$ supergravity coupled to an Abelian vector multiplet. We also make a few initial steps towards the identification of dual CFT$_2$ candidates. Specifically, we study the Kaluza-Klein spectrum of the spin two and certain vector fluctuations that are expected to be dual to the stress-energy tensor, SU(2) R current and several other BPS operator families in the dual CFT$_2$., Comment: 28 pages + appendices

In this note we discuss a topological realization of the quantum teleportation protocol. Such a realization facilitates keeping track of the evolution of quantum correlations in the system. It is then suggested, that an implementation of a similar protocol can serve as a toy model of a process of information transfer between causally disconnected regions, such as the one that should take place in a unitary evolution of a quantum black hole. Hawking quanta provide the necessary entangled pairs for the teleportation channel, and the same interaction mechanism that creates the Hawking pairs, destroys the entanglement at the late stages of the evolution. Different steps of the teleportation protocol are characterized by the entropies associated with the disconnected regions, and one can introduce an analog of the Page curve for the entropy of the Hawking radiation. Some regions of the ``black hole'' interior appear to actually encode the information of the exterior, so it is natural to identify them with the ``islands'' of the semiclassical gravity analysis., Comment: significantly revised version, 8 pages, 1 figure

Classification of entanglement is an important problem in Quantum Resource Theory. In this paper we discuss an embedding of this problem in the context of Topological Quantum Field Theories (TQFT). This approach allows classifying entanglement patterns in terms of topological equivalence classes. In the bipartite case a classification equivalent to the one by Stochastic Local Operations and Classical Communication (SLOCC) is constructed by restricting to a simple class of connectivity diagrams. Such diagrams characterize quantum states of TQFT up to braiding and tangling of the ``connectome.'' In the multipartite case the same restricted topological classification only captures a part of the SLOCC classes, in particular, it does not see the W entanglement of three qubits. Nonlocal braiding of connections may solve the problem, but no finite classification is attempted in this case. Despite incompleteness, the connectome classification has a straightforward generalization to any number and dimension of parties and has a very intuitive interpretation, which might be useful for understanding specific properties of entanglement and for design of new quantum resources., Comment: 18 pages, 1 figure, version accepted to PRD. Significantly updated text following comments of referee(s). Extra references added

Recently there has been a notable progress in the study of glueball states in lattice gauge theories, in particular extrapolating their spectrum to the limit of large number of colors $N$. In this note we compare the large $N$ lattice results with the holographic predictions, focusing on the Klebanov-Strassler model. We note that glueball spectrum demonstrates approximate universality across a range of gauge theory models. Because of this universality the holographic models can give reliable predictions for the spectrum of pure $SU(N)$ Yang-Mills theories with and without supersymmetry. This is especially important for the supersymmetric theories, for which no firm lattice predictions exist yet, and the holographic models remain the most tractable approach. For non-supersymmetric pure $SU(N)$ theories with large $N$ we find an agreement within 5-8% between the lattice and holographic predictions for the mass ratios of the lightest states in various sectors. In particular both lattice and holography give predictions for the $2^{++}$ and $1^{--}$ mass ratio, consistent with the known constraints on the pomeron and odderon Regge trajectories., Comment: 18 pages, 2 figures, 5 tables. This paper is an extended version of a contribution to proceedings of the Low X 2021 conference on Elba [arXiv:2206.11624], based on a talk given at that event by one of the authors

The purpose of the Low-$x$ Workshop series is to stimulate discussions between experimentalists and theorists in diffractive hadronic physics, QCD dynamics at low $x$, parton saturation, and exciting problems in QCD at HERA, Tevatron, LHC, RHIC, and the future EIC. The central topics of the workshop, summarized in the current Proceedings, were: Diffraction in ep and e-ion collisions (including EIC physics); Diffraction and photon-exchange in hadron-hadron, hadron-nucleus, and nucleus-nucleus collisions; Spin Physics; Low-$x$ PDFs, forward physics, and hadronic final states. This Workshop has been the XXVIII edition in the series of the workshop., Comment: The 2021 edition of the Low-$x$ International Workshop took place from September 26 to October 1 in Elba, Italy. Contains arXiv:2202.03724, arXiv:2111.04515, arXiv:2112.07827, arXiv:2110.05081, arXiv:2112.11054, arXiv:2112.13794, arXiv:2111.13916, arXiv:2201.06948, arXiv:2201.05224, arXiv:2202.04207, arXiv:2205.08785

We discuss the basic problem of signal transmission in quantum mechanics in terms of topological theories. Using the analogy between knot diagrams and quantum amplitudes we calculate the transmission coefficients of the concept topological quantum devices that realize the knot topology. We observe that the problem is in different ways similar to that of transmission on quantum graphs. The desired transmission or filtering properties can be attained by the variation of the topology of the device, or an external parameter, which in our model controls the topological phase. One interesting property of the transmission coefficients is the existence of "self-averaging" phases, in which the value of the transmission coefficient is independent from all the representatives in a chosen family of knots. We briefly discuss physical realizations of the concept devices., Comment: 21 pages, 13 figures

In this paper we study the Wiedemann-Franz laws for transport in 2+1 dimensions, and the action of $Sl(2,\mathbb{Z})$ on this transport, for theories with an AdS/CMT dual. We find that $Sl(2,\mathbb{Z})$ restricts the RG-like flow of conductivities and that the Wiedemann-Franz law is $\bar L =\bar\kappa/(T\sigma)=cg_4^2\pi/3$, from the weakly coupled} gravity dual. In a self-dual theory this value is also the value of $L =\kappa/(T\sigma)$ in the weakly coupled field theory description. Using the formalism of a 0+1 dimensional effective action for both generalized $SYK_q$ models and the $AdS_4$ gravity dual, we calculate the transport coefficients and show how they can be matched at large $q$. We construct a generalization of this effective action that is invariant under $Sl(2,\mathbb{Z})$ and can describe vortex conduction and integer quantum Hall effect., Comment: 51 pages, 2 figures; references added, clarifications for comparison with reference, and about our results, added

In this paper we describe a pseudoscalar subsector of the Klebanov-Strassler model. This subsector completes the holographic reconstruction of the spectrum of the lowest-lying glueball states, which are singlet under the global symmetry group $SU(2)\times SU(2)$. We derive the linearized supergravity equations for the pseudoscalar fluctuations and analyze their spectrum. The system of equation is shown to be compatible with six eigenmodes, as expected from supersymmetry. Our numerical analysis allows to reliably extract four of the corresponding towers. Their values match well the eigenvalues of the $0^{++}$ scalar states known from an earlier work. Assuming the masses of $0^{++}$ as a reference, we compare the lightest states of the holographic spectrum with lattice calculations in the quenched QCD at $N_c=3$ and $N_c=\infty$., Comment: 54 pages, 6 figures, 5 tables -> 55 pages, 6 figures, 5 tables, references added in the second version

In this paper we construct time-dependent solutions of three-dimensional gravity in AdS space dual to systems with boundaries (BCFTs), following the AdS/BCFT prescription. Such solutions can be discussed in the context of the dynamics of first order phase transitions, or more generally, in the description of quantum quenches. As an example, we apply the holographic model to calculate the dynamics of the entanglement entropy of a local quench corresponding to a nucleation of a Euclidean bubble. As in the known 1+1 CFT examples of local cut and glue quenches, the holographic entanglement entropy grows logarithmically with time with the correct universal coefficient. However, in the bubble quench, the behavior is different at late times. The AdS/BCFT model exhibits the light-cone spreading of correlations and saturation at late times. We also find an analytical formula for the entropy at finite temperature. In the latter case the initial logarithmic growth is followed by the linear law at intermediate times., Comment: 18 pages, 9 figures, In this version the relation between cut and glue quenches and the considered quench protocol was clarified. The title of the paper was changed to reflect the difference. Appropriate references added

The theory of elastic rods can be used to describe certain geometric and topological properties of the DNA molecules. A similar effective field theory approach was previously suggested to describe the conformations and dynamics of proteins. In this letter we report a detailed study of the basic features of a version of the proposed model, which assumes proteins to be very long continuous curves. In the most appealing case, the model is based on a potential with a pair of minima corresponding to helical and strand-like configurations of the curves. It allows to derive several predictions about the geometric features of the molecules, and we show that the predictions are compatible with the phenomenology. While the helices represent the ground state configurations, the abundance of beta strands is controlled by a parameter, which can either completely suppress their presence in a molecule, or make them abundant. The few-parameter model investigated in the letter rather represents a universality class of protein molecules. Generalizations accounting for the discrete nature and inhomogeneity of the molecules presumably allow to model realistic cases., Comment: 5 pages, 4 figures. This paper contains a discussion of an effective field theory model in application to description of the protein structure. A longer version containing technical details was submitted to the hep-ph archive

In this paper we discuss a one-dimensional Abelian Higgs model with Chern-Simons interaction as an effective theory of one-dimensional curves embedded in three-dimensional space. We demonstrate how this effective model is compatible with the geometry of protein molecules. Using standard field theory techniques we analyze phenomenologically interesting static configurations of the model and discuss their stability. This simple model predicts some characteristic relations for the geometry of secondary structure motifs of proteins, and we show how this is consistent with the experimental data. After using the data to universally fix basic local geometric parameters, such as the curvature and torsion of the helical motifs, we are left with a single free parameter. We explain how this parameter controls the abundance and shape of the principal motifs (alpha helices, beta strands and loops connecting them)., Comment: 32 pages, 17 figures, 4 tables, references updated

We compute an upper bound on the circuit complexity of quantum states in $3d$ Chern-Simons theory corresponding to certain classes of knots. Specifically, we deal with states in the torus Hilbert space of Chern-Simons that are the knot complements on the $3$-sphere of arbitrary torus knots. These can be constructed from the unknot state by using the Hilbert space representation of the $S$ and $T$ modular transformations of the torus as fundamental gates. The upper bound is saturated in the semiclassical limit of Chern-Simons theory. The results are then generalized for a family of multi-component links that are obtained by "Hopf-linking" different torus knots. We also use the braid word presentation of knots to discuss states on the punctured sphere Hilbert space associated with 2-bridge knots and links. The calculations present interesting number theoretic features related with continued fraction representations of rational numbers. In particular, we show that the minimization procedure defining the complexity naturally leads to regular continued fractions, allowing a geometric interpretation of the results in the Farey tesselation of the upper-half plane. Finally, we relate our discussion to the framework of path integral optimization by generalizing the original argument to non-trivial topologies., Comment: 35 + 8 pages, 11 Figures; V3: fixed sec. 3 and 4 to carefully distinguish between topological and circuit complexity

Protein molecules can be approximated by discrete polygonal chains of amino acids. Standard topological tools can be applied to the smoothening of the polygons to introduce a topological classification of proteins, for example, using the self-linking number of the corresponding framed curves. In this paper we add new details to the standard classification. Known definitions of the self-linking number apply to non-singular framings: for example, the Frenet framing cannot be used if the curve has inflection points. Meanwhile in the discrete proteins the special points are naturally resolved. Consequently, a separate integer topological characteristics can be introduced, which takes into account the intrinsic features of the special points. For large number of proteins we compute integer topological indices associated with the singularities of the Frenet framing. We show how a version of the Calugareanu's theorem is satisfied for the associated self-linking number of a discrete curve. Since the singularities of the Frenet framing correspond to the structural motifs of proteins, we propose topological indices as a technical tool for the description of the folding dynamics of proteins., Comment: 17 pages, many figures

In this paper we review the AdS/BCFT proposal of T. Takayanagi for holographic description of systems with boundaries, in particular, boundary conformal field theories (BCFTs). Motivated by better understanding of the proposed duality we employ entanglement entropy as a probe of familiar properties of impurities and defects. Using the dual gravity description, we check that in two spacetime dimensions the impurity entropy does not depend on a particular state of the theory, which is a well-known CFT result. In three dimensions different, and not necessarily equivalent, definitions of the defect entropy can be given. We compute the entanglement entropy of a line defect at finite temperature and compare it with earlier calculations of the thermodynamical entropy. The results indicate that the entanglement entropy flows to the definition of the entropy as the Bekenstein-Hawking entropy associated to a portion of the black horizon, which we call impurity "shadow". Geometric configurations, which we discuss, provide examples of RG flows of the defect entropies. We outline the connection between the geometric picture of the RG flows and examples of lattice calculations. We also discuss some new generalizations of the AdS/BCFT geometries., Comment: 29 pages, many figures. V3 uses an improved method of calculating the entanglement entropy

Non-relativistic field theories with anisotropic scale invariance in (1+1)-d are typically characterized by a dispersion relation $E\sim k^{z}$ and dynamical exponent $z>1$. The asymptotic growth of the number of states of these theories can be described by an extension of Cardy formula that depends on $z$. We show that this result can be recovered by counting the partitions of an integer into $z$-th powers, as proposed by Hardy and Ramanujan a century ago. This gives a novel relationship between the characteristic energy of the dispersion relation with the cylinder radius and the ground state energy. For free bosons with Lifshitz scaling, this relationship is shown to be identically fulfilled by virtue of the reflection property of the Riemann $\zeta$-function. The quantum Benjamin-Ono$_{2}$ (BO$_{2}$) integrable system, relevant in the AGT correspondence, is also analyzed. As a holographic realization, we provide a special set of boundary conditions for which the reduced phase space of Einstein gravity with a couple of $U(1)$ fields on AdS$_3$ is described by the BO$_{2}$ equations. This suggests that the phase space can be quantized in terms of quantum BO$_{2}$ states. Indeed, in the semiclassical limit, the ground state energy of BO$_{2}$ coincides with the energy of global AdS$_{3}$, and the Bekenstein-Hawking entropy for BTZ black holes is recovered from the anisotropic extension of Cardy formula., Comment: 21 pages. v2: minor corrections + extended discussion on the generalized modular invariance in the intro; matches published version

In this paper the low temperature zero-frequency transport in a 2+1-dimensional theory dual to a dyonic black hole is discussed. It is shown that transport exhibits topological features: the transverse electric and heat conductivities satisfy the Wiedemann-Franz law of free electrons; the direct heat conductivity is measured in units of the central charge of the dual CFT, while the direct electric conductivity vanishes; the thermoelectric conductivity is non-zero at vanishing temperature, while the linear in temperature behaviour, controlled by the Mott relation, is subleading. Provided that the entropy of the black hole, and the dual system, is non-vanishing at zero temperature, the observations indicate that the dyonic black hole describes a "classical" limit of a highly degenerate topological state, in which the black hole charge measures the density of excited non-abelian quasiparticles., Comment: 5 pages, 1 figure

The Frenet equation governs the extrinsic geometry of a string in three-dimensional ambient space in terms of the curvature and torsion, which are both scalar functions under string reparameterisations. The description engages a local SO(2) gauge symmetry, which emerges from the invariance of the extrinsic string geometry under local frame rotations around the tangent vector. Here we inquire how to construct the most general SO(2) gauge invariant Hamiltonian of strings, in terms of the curvature and torsion. The construction instructs us to introduce a long-range (self-) interaction between strings, which is mediated by a three dimensional bulk gauge field with a Chern-Simons self-interaction. The results support the proposal that fractional statistics should be prevalent in the case of three dimensional string-like configurations., Comment: 5 pages

In a wide class of holographic models, like the one proposed by Sakai and Sugimoto, baryons can be approximated by instantons of non-abelian gauge fields that live on the world-volume of flavor D-branes. In the leading order, those are just the Yang-Mills instantons, whose solutions can be obtained from the celebrated ADHM construction. This fact can be used to study various properties of baryons in the holographic limit. In particular, one can attempt to construct a holographic description of the cold dense nuclear matter phase of baryons. It can be argued that holographic baryons in such a regime are necessarily in a solid crystalline phase. In this review we summarize the known results on the construction and phases of crystals of the holographic baryons., Comment: 66 pages, 16 figures. Prepared for the special issue "Skyrmion" of the IJMPB, edited by M. Rho and I. Zahed

In this note we examine a possible extension of the matrix integral representation of knot invariants beyond the class of torus knots. In particular, we study a representation of the SU(2) quantum Racah coefficients by double matrix integrals. We find that the Racah coefficients are mapped to expansion coefficients in some basis of double integrals. The transformed coefficients have a number of interesting algebraic properties., Comment: 5 pages, 7 figures

A proposal to describe gravity duals of conformal theories with boundaries (AdS/BCFT correspondence) was put forward by Takayanagi few years ago. However interesting solutions describing field theories at finite temperature and charge density are still lacking. In this paper we describe a class of theories with boundary, which admit black hole type gravity solutions. The theories are specified by stress-energy tensors that reside on the extensions of the boundary to the bulk. From this perspective AdS/BCFT appears analogous to the fluid/gravity correspondence. Among the class of the boundary extensions there is a special (integrable) one, for which the stress-energy tensor is fluid-like. We discuss features of that special solution as well as its thermodynamic properties., Comment: 18 pages, 4 figures (7 pdf-files). Save and view with Adobe Reader if images appear corrupted in the browser

Lattice simulations currently present the only way to access nonperturbative data in strongly coupled theories from a first principle calculation. However, in supersymmetric theories this valuable tool is not available due to the technical sign problem. We are going to demonstrate that in the case of glueball spectra a good quantitative estimate for the lightest states of low spin can be obtained by means of the holographic approach. We will review the results of the calculation in the singlet glueball sector of the N=1 supersymmetric Klebanov-Strassler model. We come up with a prediction of the spectrum of lightest glueballs in (large Nc) N=1 supersymmetric Yang-Mills theory., Comment: 10 pages, 2 figures; Proceedings of the workshop "Low X Physics", Israel, May 30 - June 4, 2013

In this paper we study a simple gravity model dual to a (2+1)-dimensional system with a boundary at finite charge density and temperature. In our naive AdS/BCFT extension of a well known AdS/CFT system a non-zero charge density must be supported by a magnetic field. As a result, the Hall conductivity is a constant inversely proportional to the coefficients of pertinent topological terms. Since the direct conductivity vanishes, such behaviors resemble that of a quantum Hall system with Fermi energy in the gap between the Landau levels. We further analyze the properties stemming from our holographic approach to a quantum Hall system. We find that at low temperatures the thermal and electric conductivities are related through the Wiedemann-Franz law, so that every charge conductance mode carries precisely one quantum of the heat conductance. From the computation of the edge currents we learn that the naive holographic model is dual to a gapless system if tensionless RS branes are used in the AdS/BCFT construction. To reconcile this result with the expected quantum Hall behavior we conclude that gravity solutions with tensionless RS branes must be unstable, calling for a search of more general solutions. We briefly discuss the expected features of more realistic holographic setups., Comment: 20 pages, 2 figures

In the large N limit cold dense nuclear matter must be in a lattice phase. This applies also to holographic models of hadron physics. In a class of such models, like the generalized Sakai-Sugimoto model, baryons take the form of instantons of the effective flavor gauge theory that resides on probe flavor branes. In this paper we study the phase structure of baryonic crystals by analyzing discrete periodic configurations of such instantons. We find that instanton configurations exhibit a series of "popcorn" transitions upon increasing the density. Through these transitions normal (3D) lattices expand into the transverse dimension, eventually becoming a higher dimensional (4D) multi-layer lattice at large densities. We consider 3D lattices of zero size instantons as well as 1D periodic chains of finite size instantons, which serve as toy models of the full holographic systems. In particular, for the finite-size case we determine solutions of the corresponding ADHM equations for both a straight chain and for a 2D zigzag configuration where instantons pop up into the holographic dimension. At low density the system takes the form of an "abelian anti-ferromagnetic" straight periodic chain. Above a critical density there is a second order phase transition into a zigzag structure. An even higher density yields a rich phase space characterized by the formation of multi-layer zigzag structures. The finite size of the lattices in the transverse dimension is a signal of an emerging Fermi sea of quarks. We thus propose that the popcorn transitions indicate the onset of the "quarkyonic" phase of the cold dense nuclear matter., Comment: v3, 80 pages, 18 figures, footnotes 5 and 7 added, version to appear in the JHEP

We propose a holographic model of baryon interactions based on non-supersymmetric D7-anti-D7 flavor branes embedded in the Klebanov-Strassler background. The baryons are D3-branes wrapping the 3-sphere of the conifold with M strings connecting the D3 and the flavor branes. Depending on the location of the latter there are two possibilities: the D3 either remains separate from the flavor branes or dissolves in them and becomes a flavor instanton. The leading order interaction between the baryons is a competition between the attraction and the repulsion due to the sigma and omega mesons. The lightest 0++ particle sigma is a pseudo-Goldstone boson associated with the spontaneous breaking of scale invariance. In a certain range of parameters it is parametrically lighter than any other massive state. As a result at large distances baryons attract each other. At short distances the potential admits a repulsive core due to an exchange of the omega vector meson. We discuss baryon coupling to glueballs, massive mesons and pions and point out the condition for the model to have a small binding energy., Comment: 36 pages, 4 figures

In this note we study vector fluctuations over the Klebanov-Strassler type IIB supergravity solution that are even under the I-conjugation. We are interested only in the states invariant under the global SU(2)x SU(2) symmetry. Apart from the glueball dual to the R-current there is one more 1++ state, which is a member of a massive vector multiplet containing also a scalar 0++. Combined with previous results, our analysis allows to complete the list of low energy singlet supermultiplets in the Klebanov-Strassler theory., Comment: 12 pages, 2 figures

We perform a perturbative (near-critical) analysis of the stability of an asymptotically Schroedinger Reissner-Nordstrom black hole with respect to generation of charged scalar hair. We find that apart from the expected instability at low temperatures typical of holographic models of superconductivity, in the presence of certain operators a similar instability appears as well at high temperatures. We propose that the reason for such a phase diagram could be due to peculiar features of the dual gauge theory or the failure of the model to provide a consistent holographic dual of a non-relativistic superconductor., Comment: 18 pages, 6 figures

It is possible that the standard model is coupled, through new massive charged or colored particles, to a hidden sector whose low energy dynamics is controlled by a pure Yang-Mills theory, with no light matter. Such a sector would have numerous metastable "hidden glueballs" built from the hidden gluons. These states would decay to particles of the standard model. We consider the phenomenology of this scenario, and find formulas for the lifetimes and branching ratios of the most important of these states. The dominant decays are to two standard model gauge bosons, or by radiative decays with photon emission, leading to jet- and photon-rich signals., Comment: 34 pages, 4 figures

The Klebanov-Strassler background is invariant under the Z_2 symmetry I, which acts by exchanging the bi-fundamental fields A and B, accompanied by the charge conjugation. We study the background perturbations in the I-odd sector and find an exhaustive list of bosonic states invariant under the global SU(2)*SU(2) symmetry. In addition to the scalars identified in an earlier publication arXiv:0712.4404 we find 7 families of massive states of spin 1. Together with the spin 0 states they form 3 families of massive vector multiplets and 2 families of massive gravitino multiplets, containing a vector, a pseudovector and fermions of spin 3/2 and 1/2. In the conformal Klebanov-Witten case these I-odd particles belong to the N=1 superconformal Vector Multiplet I and Gravitino Multiplets II and IV. The operators dual to the I-odd singlet sector include those without bi-fundamental fields making an interesting connection with the pure N=1 SYM theory. We calculate the mass spectrum of the corresponding glueballs numerically and discuss possible applications of our results., Comment: 34 pages, 3 figures, 2 tables

In N=2 SYM theory with matter non-conservation of the S-charge of a BPS state under monodromies leads to so-called BPS state "decay". A mechanism for such a behavior on the semiclassical level could be established through consideration of soliton-fermion bound state. Solutions to classical equations of motion allow to observe the BPS state "decay" in vivo., Comment: 9 pages, 2 figures