This page is a glossary of terms instring theory , including related areas such assupergravity ,supersymmetry , andhigh energy physics .
-bein A suffix indicating a frame, where the first part is a German word indicating the dimension (as in zweibein, vierbein, and so on). -ino The superpartners of bosons are often denoted by the suffix -ino; for example,photon /photino . s- The superpartners of fermions are often denoted by adding s- at the beginning; for example,quark /squark . α 1. Fine-structure constant 2. Regge slope , or inverse of thestring tension How are these related?There is only one dimensional constant in string theory, and that is the inverse string tensionα ′ {\displaystyle \alpha ^{\prime }} with units of area. Sometimesα ′ {\displaystyle \alpha ^{\prime }} is therefore replaced by a lengthl s = α ′ {\displaystyle l_{s}={\sqrt {\alpha ^{\prime }}}} . The string tension is mostly defined as the fraction1 2 π α ′ . {\displaystyle {\frac {1}{2\pi \alpha ^{\prime }}}.} Tension is energy or work per unit length. In natural unitsc = 1 {\displaystyle c=1} andℏ = 1 {\displaystyle \hbar =1} , and henceα ′ {\displaystyle \alpha ^{\prime }} has dimension of length/energy or length/mass. Sinceℏ {\displaystyle \hbar } has the dimension of action, i.e. momentum times length, it follows that in natural units mass =1/length, and soα ′ {\displaystyle \alpha ^{\prime }} has the unit of area.The slopeα ′ {\displaystyle \alpha ^{\prime }} of a Regge trajectoryα ( M 2 ) {\displaystyle \alpha (M^{2})} inRegge theory is the derivative of spinS {\displaystyle S} or angular momentum with respect to mass-squared, i.e.d S d M 2 . {\displaystyle {\frac {dS}{dM^{2}}}.} Since angular momentum is moment of momentump {\displaystyle p} , i.e. length times mass withc = 1 {\displaystyle c=1} ,S {\displaystyle S} is dimensionless in natural units, andα ′ {\displaystyle \alpha ^{\prime }} has units of1 / M 2 {\displaystyle 1/M^{2}} or area like the inverse string tension.3. A Fourier coefficient of a spacetime coordinate. 4. αs is thestrong coupling constant β 1. One of the two conformal superghost fieldsβ ,γ used in the BRST quantization of the superstring 2. Euler beta function 3. Beta function describing the change of coupling constant under the renormalization group flow γ 1. Dirac matrix 2. One of the two conformal superghost fieldsβ ,γ used in the BRST quantization of the superstring 3. World-sheet metric γab (σ,τ) 4. Photon 5. Euler constant .57721... Γ 1. Lattice 2. EulerGamma function 3. Dirac matrix 4. Width of some scattering process δ 1. Kronecker delta function 2. An infinitesimal change in something; for example δL is an infinitesimal change inL Δ 1. Propagator 2. Delta baryon , a baryon with 3 light quarks and isospin 3/2 3. Laplace operator in Euclidean space or more generally a Riemannian manifold ε 1. Small positive real number 2. Antisymmetric tensor η 1. Flat Lorentzian metric on spacetime 2. Dedekind eta function , a weight 1/2 modular form 3. Eta meson , a neutral flavor meson withP C = –+ θ 1. Theta function 2. θc is theCabbibo angle 3. θw is theWeinberg angle , also called the weak mixing angle Λ 1. Cosmological constant 2. Large energy or large mass cutoff in regularization 3. Lambda baryon , a baryon with 2 light quarks and isospin 0 μ 1. Renormalization scale, with the dimensions of mass 2. Muon ν Neutrino Ξ 1. Xi baryon , a baryon with 1 light quark π 1. 3.14159... 2. Pion Π The momentum density conjugate toX ρ Rho meson , a light meson with PC = ––σ 1. Spacelike coordinate on the world-sheet 2. Scattering cross section 3. Pauli matrix 4. See#sigma model Σ 1. Sigma baryon , a baryon with 2 light quarks and isospin 1 τ 1. Timelike coordinate on the world-sheet 2. Element of theupper half plane 3. Tauon Υ Upsilon meson (bb )φ Scalar field χ Neutral-flavor heavy meson with PC = ++ ψ 1. Spinor field 2. Psi meson (cc ) Ω 1. Density of something in the universe; for example, Ων is the neutrino density 2. Omega baryon , a baryon with no light quarks ' (prime) X ′ means ∂X /∂σ.dot above letter Ẋ means ∂X /∂τ ∇ 1. A covariant derivative 2. Thedel operator. □ TheD'Alembert operator , or non-Euclidean Laplacian. [,] A commutator: [A ,B ] =AB –BA . {,} An anticommutator: {A ,B } =AB +BA . A 1. A connection 1-form 2. Short for antiperiodic, a boundary condition on strings. 3. Short foraxial vector 4. An asymmetry action A functionS on the space of fields given (formally) by the integral of the Lagrangian density over spacetime, whose stationary points are the solutions of the equations of motion. ADE Refers to the ADE classification (An ,Dn , E6 , E7 , E8 ) of simply lacedDynkin diagrams , and to several related classifications of Lie algebras, singularities and so on.ADHM Initials of Atiyah, Drinfeld, Hitchin, and Manin, as in theADHM construction of instantons. ADM Initials of Arnowitt, Deser, and Misner, as inADM energy , a way of defining the global energy in an asymptotically flat spacetime, orADM decomposition of a metric, orADM formalism . AdS Anti-de Sitter, as inanti-de Sitter space , a Lorentzian analogue of hyperbolic space AdS/CFT Anti-de Sitter/conformal field theory, especially theAdS/CFT correspondence . ALE Asymptotically locally Euclidean ALEPH ALEPH experiment at LEPAMSB Anomaly mediation supersymmetry breaking ASD Anti self-dual (connection) ATLAS TheATLAS experiment atCERN , a particle detector. axino A hypothetical supersymmetric partner of an axion.axion A hypothetical scalar particle whose mass arises from a coupling rather than from a mass term in the Lagrangian, used to resolve thestrong CP problem .b 1. One of the two conformal ghost fieldsb ,c used in the BRST quantization of the bosonic string. 2. Abottom quark . B 1. Baryon number 2. Short forboson . 3. Short forbaryon . 4. Short for backward;for example, σB is the cross section for backward scattering. 5. abottom meson . BAO Baryon acoustic oscillation BB Big Bang BBN Big Bang nucleosynthesis bino A hypothetical supersymmetric partner of the gauge field corresponding to weak hypercharge.BIon A BPS solution representing an infinite string ending on a D-brane. Named after theBorn–Infeld action . BPS A state related to theBogomol'nyi–Prasad–Sommerfield bound .BR Branching ratio BRS BRST quantization Short for Becchi, Rouet, Stora and Tyutin, who introduced theBRST quantization of gauge theories.brane Short for membrane. a higher-dimensional manifold moving in spacetime. See also p-brane, D-brane. BTZ Initials of Bañados–Teitelboim–Zanelli, as inBTZ black hole , a black hole in 2+1-dimensional gravity. BV Batalin–Vilkovisky, as inBatalin–Vilkovisky formalism . c 1. Thespeed of light , when not using units where this is 1. 2. A central charge of the Virasoro algebra or similar algebra. 3. One of the two conformal ghost fieldsb ,c used in the BRST quantization of the bosonic string. 4. AChern class . 5. Acharm quark . C 1. Charge, especially thecharge symmetry . Calabi–Yau AKähler manifold with vanishingRicci curvature , used for compactifying string theories.CAR Canonical anticommutation relations CBR Cosmic background radiation CC 1. Charged current (weak interaction). 2. Complex conjugate 3. Compatibility condition CCR Canonical commutation relation CCR and CAR algebras CDF Collider Detector at Fermilab CDM Cold dark matter CERN Conseil Européen pour la Recherche Nucléaire chargino A hypothetical charged supersymmetric partner of agauge boson .Chern–Simons 1. 2. chiral 1. Not invariant under the parity symmetry. The word comes from the Greek χειρ meaning "hand"; the terms "left-handed" and "right-handed" are often used to describe chiral objects. 2. Achiral multiplet is a type of supermutliplet of a supersymmetry algebra. CIPT Contour improved perturbation theory CKG Short for conformal Killing group. CKM TheCabibbo–Kobayashi–Maskawa matrix . CKS Short for conformal Killing spinor. CKV Short for conformalKilling vector . CFT Conformal field theory Chan–Paton AChan–Paton charge is a degree of freedom carried by an open string on its endpoints. cl 1. Short for classical (for example,S cl is the classical action). 2. CL is short for confidence limit. closed A closed string is one with no ends. CM Center of mass (frame) CMB CMBR Cosmic microwave background radiationCMS 1. TheCompact Muon Solenoid atCERN , a particle detector. 2. Short for the Center-of-Momentum System, a coordinate system where the total momentum is 0. compactification A method for reducing the apparent dimension of spacetime by wrapping the string around a compact manifold. cosmological constant The constant term of the Lagrangian, inducing a term in the action proportional to the volume of spacetimeCP Short for Charge–Parity, as inCP symmetry . CPC Short for Charge–Parity conservation. CPT Short for Charge–Parity–Time, as inCPT symmetry orCPT theorem . CPV Short for Charge–Parity violation. critical Thecritical dimension is the spacetime dimension in which a string or superstring theory is consistent; usually 26 for string theories and 10 for superstring theories. CVC Conservedvector current . CY Short for Calabi–Yau, as inCalabi–Yau manifold , a Ricci-flat Kähler manifold, often used for compactifying superstring theories. d 1. Theexterior derivative of a form. 2. Adown quark . 3. The dimension of spacetime. D 1. Short for Dirichlet, as in D-brane 2. The dimension of spacetime 3. A connection or differential operator 4. ADynkin diagram of an orthogonal group in even dimensions. 5. Acharmed meson . D0 D-brane Dp-brane Short for Dirichlet (mem)brane, a submanifold (of dimensionp +1) on which the ends of strings are constrained to lie, so that the strings satisfy Dirichlet boundary conditions.D-string A D1-brane DBI Short for Dirac–Born–Infeld, as in theDBI action , an action based on theBorn–Infeld action , a modification of the Maxwell action of electrodynamics. DDF Initials of Del Guidice, Di Vecchia, and Fubini, as inDel Guidice–Di Vecchia–Fubini operator , operators generating an oscillator algebra. DELPHI DELPHI experiment at LEP.DESY Deutsches Elektronen-Synchrotron DGLAP Initials of Dokshitzer–Gribov–Lipatov–Altarelli–Parisi who introduced theDGLAP evolution equation in QCD. Diff Diffeomorphism ordiffeomorphism group .dilatino A supersymmetric partner of the dilaton.dilaton A massless scalar particle, related to dilations of spacetime.Dirichlet Dirichlet boundary conditions on an open string say that the ends of the string are fixed (often lying on a D-brane).DIS Deep inelastic scattering DLCQ Discrete light-cone quantization DM Dark matter DØ Dp-brane Short for Dirichlet (mem)brane, a submanifold (of dimensionp +1) on which the ends of strings are constrained to lie, so that the strings satisfy Dirichlet boundary conditions.DR 1. Short fordimensional regularization . 2. Short fordimensional reduction , a way of constructing theories from simpler theories in higher dimensions, sometimes by making fields invariant under some spacelike translations. dS de Sitter, as inde Sitter space , a Lorentzian analogue of a sphere dS/CFT de Sitter/conformal field theory, especially thedS/CFT correspondence . dual resonance model An early precursor of string theory.duality A hidden connection between two different theories, such asS-duality ,T-duality ,U-duality ,mysterious duality .DY Initials of Drell–Yan, as inDY process . dyon A hypothetical particle with both electrical and magnetic charge.e 1. Euler's constant 2. A frame 3. An electron E Energy E6 E6 is the exceptional Lie algebra of rank 6 and dimension 78.E7 E7 the exceptional Lie algebra of rank 7 and dimension 133.E8 E8 the exceptional Lie algebra of rank 8 and dimension 248.eff Short for effective (field theory). EFT Effective field theory , a low-energy approximation to a theory.einbein A frame in 1 dimension elfbein A frame in 11 dimensions energy–momentum tensor A symmetric tensorT (also called the stress-energy tensor) describing the variation of the action under changes in the metric, whose components give the local energy, momentum and stress densities. In flat spacetimes it can also be given by combining the Noether currents of the translation symmetries.EWSB Electro-weak symmetry breaking. F 1. Acurvature form of a connection 2. The world-sheetfermion number . 3. Short for fermion 3. Short for forward;for example, σF is the cross section for backward scattering. F4 F4 is the exceptional Lie algebra of rank 4 and dimension 52.FCNC Flavor-changingneutral current . field A section of a fiber bundle FOPT Fixed-order perturbation theory. F-string Fundamental string F-theory Possibly an abbreviation of father theory. A 12-dimensional string theory introduced by Vafa.FRW Friedman–Robertson–Walker metric on spacetimeg 1. A metric 2. A coupling constant 3. Thegenus of a Riemann surface . 4. Agluon . G 1. Newton'sgravitational constant , sometimes writtenG N . 2. TheFermi coupling constant for weak interactions, sometimes writtenG F . 3. G n is an odd element of the Ramond or Neveu–Schwarz superalgebra. G2 The exceptional Lie algebra of rank 2 and dimension 14, or aG2 manifold with G2 holonomy.gaugino A spin 1/2 supersymmetric partner of a gauge boson. gh Abbreviation for ghost; for example,S gh is the ghost action. ghost A vector of negative norm. GKO Short for Goddard–Kent–Olive. The GKO construction, also called thecoset construction , is a way of constructing unitary discrete series representations of the Virasoro algebra. GL Ageneral linear group . gluino A hypothetical supersymmetric partner of agluon .gluon Agauge boson associated with thestrong force .GMSB Gauge mediated supersymmetry breaking. goldstino A massless spin 1/2 particle associated with spontaneous breakdown of supersymmetry, analogous to theGoldstone boson .GR General relativity graviton A conjectural spin 2 massless particle responsible for gravity.gravitino A supersymmetric partner of the graviton.Green Named forMichael Green . GS Green–Schwarz formalism, a way of incorporating supersymmetry into string theory that is supersymmetric in 10-dimensional spacetime. GSO Short for Ferdinando Gliozzi, Joël Scherk, and David A. Olive, as in theGSO projection , a projection in superstring theory that eliminates tachyons. GSW The 2-volume work on superstring theory by Green, Schwarz, and Witten. GUT Grand Unified Theory , a hypothetical theory unifying the strong and electroweak forces.GWS Glashow–Weinberg–Salem theory of theelectroweak force . GZK TheGreisen–Zatsepin–Kuzmin limit on the energy of cosmic background radiation from distant sources. h 1. The weight of a field (for example, its eigenvalue forL 0 ). 2. Hermitian; for example, h.c. stands form hermitian conjugate. H 1. TheHamiltonian . 2. TheHiggs boson . 3. TheHubble constant . Haag–Łopuszański–Sohnius theorem A theorem describing the possible supersymmetries of a quantum field theory, generalizing theColeman–Mandula theorem .Hagedorn temperature The temperature above which the partition function diverges due to the exponentially increasing number of string states.h.c. hc Hermitian conjugate HCMS Hadronic center of mass (frame) HDM Higgs doublet model HE Short for heterotic-E2 8 , a heterotic string theory based on the group E2 8 . helicity The projection of the spin of a massless particle in the direction of its momentum.HERA Hadron Elektron Ring Anlage heterotic Named after the Greek wordheterosis , meaning hybrid vigour. A hybrid of bosonic string theory and superstring theory, introduced by David Gross, Jeffrey Harvey, Emil Martinec, and Ryan Rohm in 1985.Higgs boson A massive scalar particle related to the spontaneous symmetry breaking mechanism in the electroweak theory.Higgsino A hypothetical supersymmetric partner of aHiggs boson .HO Short for heterotic-orthogonal, a heterotic string theory based on the orthogonal group O32 (R ). holographic principle HQET Hyperkähler Hyperkaehler A Riemannian manifold with holonomy contained in the compact form of the symplectic group.Hypermultiplet A type of supermultiplet (representation) of an extended supersymmetry algebra.i √–1 I Isospin .IGM Intergalactic medium inflation A hypothetical very rapid increase in the size of the very early universe.instanton A self-dual or anti-self-dual connection in a principal bundle over a four-dimensional Riemannian manifold.int Short for interaction; for example,H int might be an interaction Hamiltonian. inv Short for invisible; for example, Γinv is the width for invisible decays (those unobseverd by an experiment). J 1. A current 2. A source 3. Spin. k A momentum K Akaon (a strange meson). K3 A simply connected compact complex surface ofKodaira dimension 0K-theory A cohomology theory based on vector bundles.Kac–Moody algebra A central extension of aloop algebra .Kähler Kaehler Named afterErich Kähler 1. AKähler manifold is a complex manifold with a compatible Riemannian metric. 2. AKähler metric is the metric on a Kähler manifold. 3. AKähler potential is a function of superfields used to construct a Lagrangian. Kalb–Ramond field KK Kaluza–Klein KM 1. TheKobayashi–Maskawa mechanism for CP violation. 2. Kac–Moody algebra . KZ Initials of Knizhnik and Zamolodchikov, as inKZ equation , a differential equation related to the primary fields of a current algebra. L 1. ALagrangian 2. L n is an element of theVirasoro algebra . 3. An abbreviation for left (moving modes) 4. Lepton number 5. Short for lepton L3 L3 experiment at LEP.Lagrangian (field theory) A function on the jet space of a fiber bundle.landscape The (conjectural) moduli space of all (vacuums of) string theories.LEP TheLarge Electron–Positron Collider at CERN. lepton An elementary particle of spin 1/2 that is unaffected by the strong force.LH Left-handed LHC TheLarge Hadron Collider atCERN . little string theory LL Double logarithmic LO Leading order (term)LQG Loop quantum gravity LQC Loop quantum cosmology LSP Abbreviation forlightest supersymmetric particle . LSS Large scale structure (of the universe). m A mass of a fermion. For example,m t is the mass of the top quarkt . M The mass of a boson; for example,M Z is the mass of the Z-boson. Majorana fermion Majorana spinor A fermion or spinor with a reality condition, in spacetimes of dimension 2, 3, 4 mod 8.Majorana–Weyl fermion Majorana–Weyl spinor A half-spinor with a reality condition, in spacetimes of dimension 2 mod 8.Mandelstam variable A sum or difference of two of the four incoming or outgoing momenta of a 2-particle interaction.matrix theory M(atrix) theory One of several non-perturbative formulations of string theory or M-theory using infinite matrices.M-brane membrane A higher dimensional analogue of a string.MC Monte Carlo integration MCG minimal model Certain solvableconformal field theories . Mirror symmetry (string theory) A partly conjectural relation between a type IIA superstring theory compactified on a Calabi–Yau manifold and a type IIB superstring theory compactified on a different "mirror" Calabi–Yau manifold.MLLA Modified leading logarithm approximation. MNS Maki–Nakagawa–Sakata matrix for neutrino mixingmonopole A hypothetical particle similar to a "magnet with only one pole".Montonen–Olive duality An early case ofS-duality .MS minimal subtraction (a renormalization scheme).MS is themodified minimal subtraction scheme .MSM Abbreviation forminimal standard model . MSSM Abbreviation forminimal supersymmetric standard model . mSUGRA Minimal model of supergravity .M-theory An 11-dimensional theory introduced in the second string theory revolution to unify the 5 known superstring theories. The letter M has been said to stand for membrane, matrix, magic, mystery, monster, and so on.MSW Mikheyev–Smirnov–Wolfenstein effect concerning neutrino oscillations in matter.multiplet A linear representation of a Lie algebra or group. A collection of elementary particles corresponding to a basis of a representation. N 1. The number of times each irreducible real spinor representation appears in the fermionic part of asupersymmetry algebra orsuper Minkowski space . It is often used in the description of anextended supersymmetry algebra, as inN=2 superconformal algebra and so on. 2. Anucleon , a baryon with 3 light quarks and isospin 1/2 (such as aproton orneutron ). 3. The number of some type of particle. Nambu–Goto action An action for strings, proportional to the area of the worldsheet.NC Neutral current (weak interaction). Neumann Neumann boundary conditions on an open string say that the momentum normal to the boundary of the world-sheet is zero.neutralino A hypothetical supersymmetric partner of agauge boson with zero charge.Neveu Named forAndré Neveu . Neveu–Schwarz algebra A supersymmetric extension of theVirasoro algebra , similar to theRamond algebra .NG 1. Short for Nambu–Goto, as inNambu–Goto action . 2. Short for Nambu–Goldstone, as inNambu–Goldstone boson . NLL Next to leading logarithmic (term). NLO Next to leading order (term). NLSP next-to-lightest sypersymmetric particle NMSSM Next-to-Minimal Supersymmetric Standard Model .NNLL Next to next to leading logarithmic (term). NNLO Next to next to leading order (term). NNNLL Next to next to next to leading logarithmic (term). no-ghost theorem A theorem stating that some hermitian form is positive semidefinite, in other words has no ghosts (negative norm vectors). The name is a word-play onno-go theorem .NR Non-relativistic NRQCD Non-relativistic quantum chromodynamics NS Neveu–Schwarz, especially theNeveu–Schwarz algebra NS–NS A sector with Neveu–Schwarz conditions on left and right moving modes. NS–R A sector with Neveu–Schwarz conditions on left moving modes and Ramond conditions on right moving modes. NUT The initials of E. Newman, L. Tamburino, and T. Unti, mainly used inTaub–NUT vacuum , a solution to Einsteins' equations. O Anorthogonal group OCQ Short for old covariant quantization OPAL TheOPAL detector at LEP. open An open string is one with two ends. OPE operator product expansion A description of short-distance singularities of fields.orbifold Something that looks locally like a manifold quotiented by the action of a finite group.OSp ALie superalgebra . p A momentum P 1. Parity, especially theparity symmetry . 2. Short for periodic, a boundary condition on strings (as opposed to A for antiperiodic). 3. Pseudoscalar (current) 4. Momentum 5. One of the bosonic elements of asupersymmetry algebra . p -braneAp +1 dimensional membrane, wherep is a non-negative integer. The dimension of membranes is often given by their space dimension, which is 1 less than their full spacetime dimension. PCAC partially conserved axial vector current PDF Parton distribution function .PDG Particle Data Group .photino A hypothetical supersymmetric partner of the photon.photon The neutral spin 1 gauge boson of the electromagnetic field.PMNS Pontecorvo–Maki–Nakagawa–Sakata matrix for neutrino mixingPolyakov action A modification of the Nambu–Goto action for strings that eliminates the square root.PQ Peccei–Quinn, as inPeccei–Quinn theory . pQCD PQCD Perturbativequantum chromodynamics . prepotential A function used to construct the vector superfield insupersymmetric gauge theory andSeiberg–Witten theory . primary field A field killed by the positive weight operators of the Virasoro algebra (or similar algebra); in other words, a lowest weight vector. Princeton string quartet David Gross ,Jeffrey Harvey ,Emil Martinec , andRyan Rohm , who introduced theheterotic string in 1985.PSL Projective special linear group .q Aquark . Q 1. TheBRST operator . 2. A charge 3. One of the fermionic generators of asupersymmetry algebra . quark A strongly interacting elementary particle of spin 1/2.QCD QED R 1. Short for Ramond, as inRamond sector . 2. A curvature tensor 3. An abbreviation for right (moving modes). 4. A radius 5. R-symmetry is a symmetry ofextended supersymmetry algebras. Ramond Named forPierre Ramond . Ramond algebra A supersymmetric extension of theVirasoro algebra , similar to theNeveu–Schwarz algebra .Rarita–Schwinger Refers to spin 3/2 fermions.Regge 1. PhysicistTullio Regge . 2. Regge trajectory : the squared mass of a hadronic resonance is roughly linear in the spin, with the constant of proportionality called theRegge slope . revolution Any new idea in string theory. In particular thefirst superstring revolution refers to the discoveries in the mid 1980s such as the cancellation of gravitational anomalies and theheterotic string , and thesecond superstring revolution refers to the discoveries in the mid 1990s, such asD-branes ,M-theory , and matrix theory and theAdS/CFT correspondence . RG Renormalization group .RGE Renormalization group equation.RH Right-handed R–NS A sector with Ramond conditions on left moving modes and Neveu–Schwarz conditions on right moving modes. RNS Ramond–Neveu–Schwarz, as inRNS formalism , a way of incorporating supersymmetry into string theory that is supersymmetric on the world sheet. R-parity AZ 2 symmetry of supersymmetric models.R-R Short forRamond–Ramond sector s 1. Astrange quark . 2. AMandelstam variable S 1. An action 2. Ascattering matrix . 3. The transformation τ → –1/τ of the upper half plane 4. Scalar (current) 5. Short forsuper orsupersymmetric S-brane A brane similar to a D-brane, with Dirichlet boundary conditions in the time direction. S-duality Strong–weak duality, astring duality relating theories with a large coupling constant to theories with a small coupling constantSBB StandardBig Bang model of the universe SCFT Superconformal field theory , a supersymmetric extension of conformal field theorySchwarz Named forJohn Henry Schwarz Seiberg duality SGA Abbreviation forSpectrum-generating algebra short supermultiplet A supermultiplet (representation) related toBPS states sigma model A classical or quantum model based on the maps from a base manifold to a target manifold.SL Special linear group SLAC Stanford Linear Accelerator Center SLC Stanford Linear Collider slepton Hypothetical supersymmetric partner of a leptonSM sneutrino Hypothetical supersymmetric partner of a neutrinoSO Special orthogonal group Sp Symplectic group sphaleron Static solution to the electroweak field equationssquark Supersymmetric partner of a quark.SSB Spontaneous symmetry breaking SSM Standard solar model stress–energy tensor Alternative name for the#energy–momentum tensor . string field theory SU Special unitary group SUGRA Short forsupergravity superconformal algebra A supersymmetric analogue of the Virasoro algebra of conformal symmetries in 2 dimensionssuperfield A supersymmetric analogue of a quantum or classical fieldsupergravity A supersymmetric extension of general relativitysupermultiplet A representation of asupersymmetry algebra superpotential A function of chiral superfield not depending on their superderivatives or spacetime derivatives, used to form a Lagrangian.superspace A supersymmetric analogue of spacetimesuperstring A supersymmetric analogue of a stringsupersymmetry A generalization of aLie superalgebra , where the Lie bracket [a ,b ] is sometimes given byab +ba rather thanab –ba .SUSY An abbreviation forsupersymmetry . SYM Supersymmetric Yang–Mills t 1. Atop quark . 2. AMandelstam variable . 3. Time. T 1. Theenergy–momentum tensor . 2. Time, especially thetime symmetry . 3. The transformation τ → τ+1 of the upper half plane. 4. A torus. 5. The string tension. 6. Temperature. 7. Tensor (current) T-duality Astring duality relating theories on a large spacetime to theories on a small spacetime. In particular it exchanges type IIA and IIB superstring theory.tachyon A particle of imaginary mass moving faster than light.ToE TOE Theory of everything type I type II type IIA type IIB A type of superstring or the corresponding low-energy supergravity theory. The Roman numeral I or II refers to the number ofd =10 supersymmetries, and types IIA or IIB are distinguished by whether the supersymmetries of left and right movers have opposite or identical chiralities.u 1. Anup quark . 2. AMandelstam variable . U Aunitary group . U-duality Short for "unified duality". Astring duality relating two different string theories.UED Universal extra dimensions UV Short for ultra-violet, often referring to short-distance singularities. V 1. Avertex operator . 2. Vector (current) V-A Vector-Axial vector vector superfield A type ofsuperfield related tovector supermultiplets . VEV Vacuum expectation value of an operator.vielbein A frame vierbein A frame in 4 dimensions. Sometimes used for a frame in an arbitrary number of dimension by authors who do not care that "vier" means four in German. Veneziano amplitude TheEuler beta function interpreted as a scattering amplitude.vertex operator Virasoro algebra A central extension of theWitt algebra of polynomial vector fields on a circle.w A complex number W AW-boson W-algebra A sort of generalization of the Virasoro algebraWeyl 1. Named afterHermann Weyl 2. AWeyl transformation is a rescaling of the world-sheet metric. 3. Weyl spinor , an element of a half-spin representation in even spacetime dimensions. WIMP Weakly interacting massive particle wino A hypothetical supersymmetric partner of theW-boson .Witten Named forEdward Witten . WMAP Wilkinson Microwave Anisotropy Probe world sheet The 2-dimensional subset of spacetime swept out by a moving string. world-volume Thep +1-dimensional spacetime volume swept out by ap -brane, as in world-volume action. WZNW WZW Initials of Wess, Zumino, (Novikov), and Witten, as in theWZW model , a σ-model with a group as the target space. x A real number X Used for coordinates in Minkowski space. y A real number YBE Yang–Baxter equation YM Yang–Mills z A complex number Z 1. A partition function 2. TheZ boson . An element of the center of anextended supersymmetry algebra . ZEUS zino A hypothetical supersymmetric partner of the Z-boson.zweibein A frame in 2 dimensions Becker, Katrin,Becker, Melanie , andJohn H. Schwarz (2007)String Theory and M-Theory: A Modern Introduction . Cambridge University Press.ISBN 0-521-86069-5 Binétruy, Pierre (2007)Supersymmetry: Theory, Experiment, and Cosmology . Oxford University Press.ISBN 978-0-19-850954-7 . Dine, Michael (2007)Supersymmetry and String Theory: Beyond the Standard Model . Cambridge University Press.ISBN 0-521-85841-0 . Paul H. Frampton (1974).Dual Resonance Models . Frontiers in Physics.ISBN 0-8053-2581-6 .Michael Green ,John H. Schwarz andEdward Witten (1987)Superstring theory . Cambridge University Press. The original textbook.Kiritsis, Elias (2007)String Theory in a Nutshell . Princeton University Press.ISBN 978-0-691-12230-4 . Johnson, Clifford (2003).D-branes . Cambridge: Cambridge University Press.ISBN 0-521-80912-6 . Polchinski, Joseph (1998)String Theory . Cambridge University Press.Szabo, Richard J. (Reprinted 2007)An Introduction to String Theory and D-brane Dynamics . Imperial College Press.ISBN 978-1-86094-427-7 . Zwiebach, Barton (2004)A First Course in String Theory . Cambridge University Press.ISBN 0-521-83143-1 . Contact author for errata.