FEYN CALC GUIDE

FeynCalc

FeynCalc is a Mathematica package for algebraic calculations in Quantum Field Theory and semi-automatic evaluation of Feynman Diagrams

ReferenceReference

Basic objects

Abbreviation gives a shortname for name (in HoldForm)

AlphaStrong in QCD

AlphaFS fine-strucutre constant

AntiQuarkField, QuarkField name of a fermionic field

CA, CF Casimir operator eigenvalues of SU(N)

ChiralityProjector denotes or

DeltaFunction, DeltaFunctionPrime, DeltaFunctionDoublePrime Dirac delta function and its derivatives

DiracGamma, DiracMatrix, DiracSlash, GA, GA5, GS, GAD, GSD, GAE, GSE representation of Dirac matrices and slashes

DiracGammaT tranpose of a Dirac matrix

DiracSigma denotes

DiracSpinor, Spinor, SpinorU, SpinorUBar, SpinorV, SpinorVBar denotes spinors

Eps, LC, LCD, LeviCivita totally antisymmetric epsilon (Levi-Civita) tensor

Epsilon ϵ from dimensional regularization

ExplicitLorentzIndex, LorentzIndex Lorentz index

ExplicitSUNIndex, SUNIndex SU(N) adjoint index

ExplicitSUNFIndex, SUNFIndex SU(N) fundamental index

FAD, FeynAmpDenominator denominator of Feynman amplitudes

FCPartialD, LeftPartialD, LeftRightPartialD, LeftRightPartialD2, RightPartialD partial derivatives acting on operators

FourVector, FV, FVD, FVE representation of 4-vectors

GaugeField name of a gauge field

GaugeXi gauge parameter ξ

GluonField name of a gluon field

Gstrong QCD coupling constant

Li2 dilog function

Li3 trilog function

Momentum internal representation of momenta

MetricTensor, MT, MTD, MTE representation of the metric tensor

Nf denotes the number of flavors

Pair special pairing used in the internal representation to represent the metric, 4-vectors or scalar products

Polarization internal representation of polarizations

PolarizationVector polarization vector

PlusDistribution a special distribution

PropagatorDenominator, PD internal representation of propagator denominators

QuantumField generic name of a quantum field

ScaleMu μ scale in dimensional regularization

SD, SUNDelta Kronecker delta for adjoint SU(N) indices

SDF, SUNFDelta Kronecker delta for fundamental SU(N) indices

SmallDelta, SmallEpsilon denotes some small positive numbers

SmallVariable small variable to be used as a regulator in PaVe functions

SP, SPD, SPE denotes scalar products of 4-momenta

SUND structure constant in SU(N)

SUNF structure constant in SU(N)

SUNN in SU(N)

SUNT, SUNTF of SU(N) in the fundamental representation

Tf group constant n SU(N)

Zeta2 denotes

Basic functions

Cases2 alternative to Cases

Combine alternative to Together

Complement1 alternative to Complement

Collect2, Collect3 alternatives to Collect

DataType defines data types

Expand2 alternative to Expand

Explicit inserts explicit expressions for certain objects

Factor1, Factor2 alternatives to Factor

FCAntiSymmetrize antisymmetrizes with respect to the given variables

FCE, FeynCalcExternal converts the expression to the external FeynCalc representation

FCF, FeynCalcForm changes the printed output to an easy to read form.

FCI, FeynCalcInternal converts the expression to the internal FeynCalc representation

FCSplit, PartitHead, SelectFree, SelectNotFree alternative to Select

FCSymmetrize symmetrizes with respect to the given variables

FreeQ2 alternative to FreeQ

FRH alternative to ReleaseHold

Isolate replaces expressions by abbreviations

Map2 alternative to Map

MemSet memoization depending on the amount of free RAM

NTerms alternative to Length

NumericalFactor gives overall numerical factor

NumericQ1 alternative to NumericQ

Power2 alternative to Power

PowerFactor, PowerSimplify simplification of expressions with exponents

Series2, Series3 alternatives to Series

Solve2, Solve3 alternatives to Solve

SumP, SumS, SumT different summations

Lorentz tensors

Amputate amputates 4-vectors, Dirac matrices or Levi-Civita tensors

ChangeDimension changes dimension of Lorentz indices and momenta

CompleteSquare completes the square of a second order polynomial in the momentum x

Contract contracts Lorentz indices of tensors and Dirac matrices

EpsEvaluate applies total antisymmetry and linearity to all Levi-Civita tensors

ExpandScalarProduct expands scalar products of sums of momenta

FCClearScalarProducts removes all user-specific specific definitions of scalar products

FCRenameDummyIndices renames dummy Lorentz and SU(N) indices

FourDivergence calculates partial derivative with respect to a 4-vector

FourLaplacian calculates the Laplacian

MomentumCombine, MomentumCombine2 inverse operations to MomentumExpand and ExpandScalarProduct

MomentumExpand expands Momentum[a+b+ ...]

PairContract, PairContract2, PairContract3 like Pair but with local contraction properties

ScalarProduct defines scalar products of 4-vectors

SetMandelstam defines the Mandelstam variables

TensorFunction defines an unspecified Lorentz tensor

TrickMandelstam simplifies the expression by eliminating one of the Mandelstam variables

Uncontract uncontracts Lorentz indices of tensors and Dirac matrices

Dirac algebra

Anti5 anticommutes all matrices to the left or to the right

Chisholm substitutes products of 3 Dirac matrices by the Chisholm identity

DiracEquation applies the Dirac equation

DiracGammaCombine inverse operation to DiracGammaExpand

DiracGammaExpand expands sums of momenta contracted with Dirac matrices

DiracOrder orders the Dirac matrices in expression alphabetically

DiracReduce reduces all 4-dimensional Dirac matrices to the standard basis (SPVAT-decomposition)

DiracSigmaExplicit inserts the explicit definition of DiracSigma

DiracSimplify simplifies products of Dirac matrices and expands non-commutative products

DiracTrace computes traces of Dirac matrices

DiracTrick contracts Dirac matrices with each other and performs several simplifications but no expansions

EpsChisholm substitutes Chisholm identity for a Dirac matrix contracted with a Levi-Civita tensor

Schouten applies Schouten identity

ToLarin substitutes according to the Larin scheme

Algebra of non-commutative objects

AntiCommutator defines an anti-commutator

Calc, Trick multiple simplifications for Dirac and SU(N) algebra

Commutator defines a commutator

CommutatorExplicit substitutes explicit definitions of Commutator and AntiCommutator

DeclareNonCommutative declares non-commutative objects

DotExpand expands Dot products

DotSimplify expands and reorders noncommutative terms

NonCommFreeQ, NonCommQ checks if the expression contains non-commutative quantities

TR, Tr2 calculates Dirac and possibly also SU(N) traces

UnDeclareNonCommutative undeclares non-commutative objects

SU(N) algebra

CalcColorFactor calculates the color factor

SUNDeltaContract contracts Kronecker deltas with adjoint color indices

SUNFDeltaContract contracts Kronecker deltas with fundamental color indices

SUNSimplify, SUNFSimplify simplifies expressions that contain SU(N) matrices

SUNTrace computes traces over SU(N) matrices

Loop integrals

A0 Passarino-Veltman 1-point integral (tadpole)

Apart2 partial fractions loop integrals (only very simple cases)

ApartFF partial fractions arbitrary loop integrals

B0, B00, B1, B11 Passarino-Veltman 2-point integrals (bubbles)

C0 Passarino-Veltman 3-point integrals (triangles)

D0 Passarino-Veltman 4-point integrals (boxes)

DB0 derivative of B0 with respect to the external momentum

DB1 derivative of B1 with respect to the external momentum

FCApart backend of ApartFF, works only on single loop integrals

FCIntegral head of loop integrals

FCLoopBasisIncompleteQ checks if the propagators of a loop integral do not form a basis

FCLoopBasisOverdeterminedQ checks if the propagators of a loop integral are linearly dependent

FCLoopBasisFindCompletion determines propagators that need to be included in the loop integral to ensure that its propagators form a basis

FCLoopCanonicalize auxiliary function that canonicalizes free Lorentz indices of 1-loop integrals

FCLoopExtract extracts loop integrals

FCLoopIsolate wraps loop integrals into specified heads

FCLoopSolutionList auxiliary function that processes the output of FCLoopCanonicalize

FCLoopSplit splits the expressions into pieces that contain different types of loop integrals

FCMultiLoopTID tensor reduction of multi-loop integrals (only for non-zero Gram determinants)

FeynAmpDenominatorCombine combines products of propagators

FeynAmpDenominatorSimplify simplifies loop integrals by doing shifts and detects integrals that vanish by symmetry.

FeynAmpDenominatorSplit splits all FeynAmpDenominator's into products of single propagators

FeynmanParametrize introduces Feynman parametrization for some 1-loop integrals

FromTFI ranslates TFI, TVI and TJI Tarcer-notation to FeynCalc notation

GammaExpand rewrites Gamma
[n + m]
where n is an integer

GenPaVe, PaVe denote invariant Passarino-Veltman integrals

Hill gives the Hill identity

HypergeometricAC analytically continues Hypergeometric2F1 functions

HypergeometricIR substitutes a particular integral represenetation for all Hypergeometric2F1[a,b,c,d]

HypergeometricSE

HypExplicit expresses

HypInt substitutes Hypergeometric2F1 functions by their integral definition

IFPDOff changes from IFPD representation to FeynAmpDenominator

IFPDOn changes from FeynAmpDenominator representation to IFPD

IntegrateByParts, PartialIntegrate integration by parts for particular Feynman parameter integrals

OneLoop calculates 1-loop Feynman diagram amplitudes

OneLoopSimplify simplifies 1-loop Feynman diagram amplitudes

ToHypergeometric introduces Hypergeometric2F1

PaveOrder orders the arguments of D0 in a standard way

PaVeReduce reduces Passarino-Veltman integrals down to A0, B0, C0 and D0

PropagatorDenominatorExplicit rewrites FeynAmpDenominator in terms of scalar products and masses

RussianTrick derives IBP relations for 2-loop self-energy integrals

ScalarProductCancel cancels scalar products with propagators

SimplifyDeltaFunction applies some simplifications to DeltaFunction

Sn denotes

Tdec calculates tensor decomposition formulas for loop integrals

TFIOrder orders the arguments of some TFI functions in a standard way

TID does a 1-loop tensor integral decomposition

TIDL library of tensor integral decomposition formulas

ToDistribution introduces DeltaFunction, DeltaFunctionPrime and PlusDistribution

ToFI, ToTFI converts 1- and 2-loop scalar self-energy integrals to the Tarcer notation

ToPaVe converts scalar 1-loop integrals to Passarino Veltman scalar functions

TrickIntegrate integration of some special distributions

UVPart discards UV-finite integrals

Export and import

FeynCalc2FORM displays expression in FORM syntax

FeynCalcToLaTeX generates LaTeX

FORM2FeynCalc translates teh FORM expression in file into FeynCalc notation

StringChomp chops initial and final white space of a string

Write2 writes the given settings in sequence followed by a newline to the specified output file

Feynman rules and amplitudes

BackgroundGluonVertex 3-gluon vertex in the background field gauge

ChargeConjugationMatrix charge conjugation matrix

ChargeConjugationMatrixInv inverse of ChargeConjugationMatrix

ComplexConjugate complex conjugates Feynman amplitudes

CovariantD generic covariant derivative

CovariantFieldDerivative covariant field derivative

DoPolarizationSums sums over physical polarizations of external massless vector bosons

ExpandPartialD expands DOT products of QuantumField's using the Leibniz rule

ExplicitPartialD inserts the definition for LeftRightPartialDand LeftRightPartialD2

FAPatch patches FeynArts to be compatible with FeynCalc

FCFAConvert converts a FeynArts amplitude to FeynCalc

FCPrepareFAAmp auxiliary function for a partial conversion of a FeynArts amplitude to FeynCalc.

FermionSpinSum constructs Dirac traces out of squared ampliudes with external Dirac fermions.

FeynRule determines Feynman rules from Lagrangians

FieldDerivative field derivative

FieldStrength field strength tensor

FunctionalD functional derivative

GhostPropagator ghost propagator

GluonGhostVertex gluon ghost vertex

GluonPropagator gluon propagator

GluonSelfEnergy 1-loop gluon self-energy

GluonVertex 3- and 4-gluon vertices

PolarizationSum sums over polarizations of vector bosons

QCDFeynmanRuleConvention sign convention for QCD Feynman rules

QuarkGluonVertex quark gluon vertex

QuarkPropagator quark propagator

ScalarGluonVertex scalar-scalar-gluon vertex

SMP substitutes symbols for various SM paremeters

SMVertex some SM vertices

Tables

Amplitude database of Feynman amplitudes

AnomalousDimension non-singlet one-loop contribution to the anomalous dimension in the scheme

CheckDB saves or retrieves expressions from the database

Convolute, ConvoluteTable convolution of functions

CounterTerm database of counter terms.

Gamma1, Gamma2, Gamma3, GammaEpsilon special products and expansions of Gamma functions

Integrate2, Integrate3, Integrate4, Integrate5 some integrals

InverseMellin inverse Mellin transform for some polynomials

Kummer applies Kummer relations

Lagrangian database of Lagrangians

Nielsen denotes Nielsen's polylogarithm

SimplifyPolyLog several simplifications for Log and PolyLog functions under certain assumptions

SplittingFunction database of splitting functiosn