|  Spin-Foam Models | 
In General > s.a. 2D and 3D quantum gravity;
  BF theory; lattice field theory [generalized gauge
  theory] / path-integral quantum gravity.
  * Idea: The path-integral
    counterpart of loop quantum gravity, spacetime versions of spin networks used
    either as tools to calculate amplitudes or considered as histories; It uses 2D
    complexes with faces labelled by representations of SU(2), edges labelled by
    intertwiners; States are combinations of spin networks, and amplitudes are
    often calculated as sums over spin foams σ bounded by fixed
    spin networks s and s',
W(s, s') = ∑spin foams bounded by s and s' measure(σ) Πvertices v Av(σ) ;
    The difficult part is coming up with a good proposal for the vertex amplitudes
    Av.
  @ Intros, reviews:
    Baez LNP(00)gq/99;
    Oriti RPP(01)gq;
    Livine PhD(03)gq;
    Oriti PhD(03)gq;
    Pérez CQG(03)gq;
    Miković ht/04-conf;
    Pérez in(09)gq/06;
    Alexandrov & Roche PRP(11)-a1009;
    Bonzom PhD(10)-a1009;
    Livine Hab(10)-a1101;
    Banerjee et al Sigma(12)-a1109;
    Pérez PiP-a1205,
    LRR(13)-a1205;
    Långvik a1303;
    Engle ch(14)-a1303;
    Rovelli & Vidotto 14.
  @ General references: Freidel & Louapre NPB(03)gq/02 [diffeomorphisms];
    Bojowald & Pérez GRG(10)gq/03 [anomalies and criteria];
    Oeckl gq/03-proc [general boundary approach];
    Bahr et al CQG(11)-a1010 [systematic approach, operator spin foams];
    Rovelli & Smerlak CQG(12)-a1010 [combinatorial structure, summing = refining];
    Kisielowski et al CQG(12)-a1107 [Feynman diagrammatic approach];
    Wieland CQG(14)-a1301 [Hamiltonian formulation];
    Bodendorfer & Neiman CQG(13)-a1303 [effective action, and trans-planckian regime];
    Shirazi & Engle CQG(14)-a1308 [purely geometric path integral];
    Smolin CQG(14) [general relativity as the equation of state];
    Hnybida a1411-PhD [generating functionals];
    Finocchiaro & Oriti a1812;
    Belov a1905-PhD [geometry];
    Asante et al PRL(20)-a2004 [effective models].
  @ Simplicity constraints: Alexandrov PRD(08)-a0802,
    Han & Thiemann CQG(13)-a1010 [and closure constraints];
    Banburski & Chen PRD(16)-a1512 [simpler approach];
    Han & Huang PRD(17)-a1702
      [as surface defect in SL(2,C) Chern-Simons theory].
  @ Euclidean: Reisenberger & Rovelli PRD(97)gq/96 [sum-over-surfaces lqg],
    gq/00,
    CQG(01)gq/00;
    Reisenberger gq/97;
    Iwasaki gq/00;
    Pérez NPB(01)gq/00 [finiteness];
    Bianchi et al PRD(10)-a1004 [holomorphic representation];
    Han & Zhang CQG(12)-a1109 [on a 4D simplicial complex].
  @ EPRL model: Perini a1211 [on arbitrary 2-complexes, holomorphic representation];
    Han & Krajewski CQG(14)-a1304 [path integral representation];
    Bahr & Belov PRD(18)-a1710 [volume simplicity constraint];
    Donà et al PRL(19)-a1903 [numerical study].
  @ Other Lorentzian: Baez CQG(98)gq/97;
    De Pietri NPPS(97)gq,
    gq/99-proc;
    De Pietri & Freidel CQG(99)gq/98;
    Freidel & Krasnov ATMP(98)ht;
    Iwasaki gq/99;
    Pérez & Rovelli PRD(01)gq/00,
    PRD(01)gq/00;
    Crane et al PRL(01)gq [finiteness of state sum];
    Gambini & Pullin PRD(02)gq/01 [finite theory];
    Maran gq/03,
    PRD(04)gq [and canonical quantum gravity];
    Pereira CQG(08)-a0710;
    Barrett et al CQG(10)-a0907,
    GRG(11) [graphical calculus, asymptotics];
    Conrady & Hnybida CQG(10)-a1002;
    Ding & Rovelli CQG(10)-a1006 [boundary Hilbert space and volume operator];
    Han & Zhang CQG(13)-a1109 [on a 4D simplicial complex];
    Bianchi & Ding PRD(12)-a1109 [propagator];
    Perlov a1312;
    Liu & Han a1810 [with timelike triangles];
    Asante et al a2104 [effective models].
  @ And causality: Gupta PRD(00)gq/99;
    Oriti BJP(05)gq/04-proc,
    PRL(05)gq/04 [Feynman propagator];
    Immirzi a1610 [and the Regge action];
    > s.a. causal sets [energetic causal sets]. 
  @ And lqg: Pérez & Rovelli in(11)gq/01 [transition amplitudes];
    Arnsdorf CQG(02)gq/01;
    Livine CQG(02)gq,
    Livine & Oriti NPB(03)gq/02;
    Alesci et al PRD(08)-a0807 [and physical inner product];
    Kamiński et al CQG(10)-a0909,
    Ding et al PRD(11)-a1011 [arbitrary 2-cell spin-foams];
    Marin a1003;
    Rovelli & Speziale PRD(11)-a1012;
    Bonzom PRD(11)-a1101 [and Hamiltonian constraint];
    Dupuis PhD(10)-a1104 [and semiclassical limit];
    Alexandrov et al Sigma(12)-a1112;
    Speziale & Wieland PRD(12)-a1209 [and twistorial structure];
    Engle CQG(13)-a1301 [without piecewise linearity];
    Thiemann & Zipfel CQG(14)-a1307 [spin-foam projector];
    Yang et al a2102;
    > s.a. canonical quantum gravity [covariant].
  @ Vertex amplitudes: Livine & Speziale PRD(07)-a0705,
    EPL(08)-a0708;
    Engle et al PRL(07)-a0705 [from relationship with lqg],
    NPB(08)-a0708,
    NPB(08)-a0711 [flipped, EPRL];
    Freidel & Krasnov CQG(08)-a0708;
    Engle & Pereira CQG(08)-a0710,
    PRD(09)-a0805;
    Conrady & Freidel CQG(08)-a0806 [path-integral representation];
    Khavkine a0810-wd;
    Bonzom et al CQG(10)-a0911 [recurrence relations];
    Alexandrov PRD(10)-a1004 [and canonical quantization];
    Engle PRD(13)-a1111;
    Bianchi & Hellmann Sigma(13);
    Engle & Zipfel PRD(16)-a1502 [Lorentzian];
    Mielczarek a1810 [using quantum algorithms];
    > s.a. geometry.
  @ Face amplitudes: Bianchi et al CQG(10)-a1005;
    Regoli PhD-a1104.
  @ Quantum tetrahedra: Barbieri NPB(98)gq/97;
    Baez & Barrett ATMP(99)gq;
    Livine & Speziale CQG(08)-a0711 [boundary state];
    Terno CQG(09)-a0808 [classical limit];
    Freidel et al CMP(10)-a0905 [holomorphic factorization];
    Carfora et al JPCA(09)-a1001 [6j symbol];
    Schliemann CQG(13)-a1307 [large-volume limit].
With Matter / For Other Theories
  @ General references: Steinhaus PRD(15)-a1509 [coupled intertwiner dynamics toy model].
  @ With Yang-Mills fields: Miković CQG(02)ht/01,
    CQG(03)ht/02;
    Speziale CQG(07)-a0706 [3D];
    Alexander et al PLB(12)-a1105 [and matter, unification].
  @ With fermions: Miković AIP(06)gq/05;
    Fairbairn GRG(07)gq/06 [3D];
    Dowdall & Fairbairn GRG(11)-a1003 [3D, observables];
    Bianchi et al CQG(13)-a1012 [and Yang-Mills fields];
    Han & Rovelli CQG(13)-a1101 [PCT symmetry, etc];
    Crane a1105 [extension including the standard model].
  @ With other matter: Smilga ht/04 [SO(3, 2)];
    Fairbairn & Livine CQG(07)gq [3D];
    Baccetti et al CQG(10)-a1004 [N = 1 supersymmetric];
    Fani & Kaviani IJGMP(14)-a1102 [dimensional reduction and emergence of non-gravitational fields];
    Kisielowski & Lewandowski CQG(19)-a1807 [scalar field].
  @ And strings / M-theory: Grosse & Schlesinger PLB(02) [topological quantum field theories of 3-forms].
Related Topics and  Other Variations
  > s.a. acceleration [maximal]; Pachner
  Moves; semiclassical quantum gravity.
  @ Holonomy formulation: Magliaro & Perini IJMPD(12)-a1010; 
    Bahr JPCS(12)-a1112 [and coarse graining];
    Bahr et al PRD(13)-a1208 [new holonomy formulation];
    Dittrich et al CQG(13)-a1209;
    Hellmann & Kamiński a1210 [on arbitrary triangulations, geometric asymptotics],
    JHEP(13)-a1307.
  @ Spin nets: Dittrich et al NJP(13)-a1306 [coarse graining and continuum phases];
    Dittrich et al PRD(14)-a1312 [quantum group spin nets].
  @ Classical limit: Magliaro & Perini  EPL(11)-a1108;
    Engle PLB(13)-a1201 [correct semiclassical limit];
    Vojinović GRG(13)-a1307 [issue arising from vertex amplitudes];
    Steinhaus & Thürigen a1803 [spectral dimension];
    Donà et al CQG-a1909 [numerical].
  @ Analytic continuation: Maran gq/05 [complex general relativity and various signatures];
    Han & Liu a2104 [complex critical points]. 
  @ Other variations: Zapata JMP(02) [continuum model];
    Miković IJMPA(03)gq/02-conf [quantum field theory of spin networks];
    García-Islas gq/04 [p-adic];
    Baratin & Freidel CQG(07) [and 3D Feynman diagrams for quantum field theory],
    CQG(07)ht/06 [and 4D Feynman diagrams for quantum field theory];
    Christensen et al PLB(09)-a0710 [area correlations];
    Mamone & Rovelli CQG(09)-a0904 [second-order amplitudes];
    Conrady CQG(10)-a1003 [with timelike surfaces];
    Denicola et al CQG(10)-a1005 [with topological data];
    Han JMP(11)-a1012,
    Fairbairn & Meusburger JMP(12)-a1012,
    PoS-a1112 [deformed versions];
    Bonzom & Smerlak AHP(12)-a1103 [bubble divergences];
    Magliaro & Perini CQG(11)-a1103 [curvature and discrete Einstein equations];
    Bahr et al a1103 [with finite groups]; 
    Magliaro & Perini IJMPD(13)-a1105 [and Regge gravity];
    Perini JPCS(12)-a1110;
    Dupuis et al a1201-proc [spinors and twistors];
    Bonzom & Smerlak PRL(12)-a1201 [gauge symmetries and "cellular quantization"];
    Puchta JPCS(12) [graphs and characterization of foams];
    García-Islas IJMPA(12)-a1206 [measurement and information];
    Immirzi CQG(14)-a1311 [spinor construction of amplitudes];
    Perlov a1407;
    Hnybida CQG(16)-a1508 [without spins, using generating functions instead of recoupling theory].
  @ Coarse-graining: Markopoulou CQG(03)gq/02;
    Dittrich et al NJP(12)-a1109;
    Zapata JPCS(12)-a1203;
    Dittrich & Steinhaus NJP(14)-a1311 [refining, entangling operators];
    Dittrich et al PRD(16)-a1609 [intertwiners];
    Delcamp & Dittrich a1612
      [systematic scheme for 3D lattice gauge models based on decorated tensor networks];
    Steinhaus a2007 [rev].
  @ Renormalization:
    Oeckl in(06)gq/04;
    Livine & Oriti JHEP(07)gq/05;
    Smerlak PhD(11)-a1201 [and divergences];
    Bahr a1407 [background-independent];
    Bahr & Steinhaus PRL(16)-a1605 [evidence for a phase transition],
    PRD(17)-a1701 [hypercuboidal renormalization].
  @ Perturbations: Baez gq/99;
    Martins & Miković Sigma(11)-a0911. 
  @ Other types of spacetimes: Han & Zhang PRD(16)-a1606 [near a classical curvature singularity];
    > s.a. 3D black holes.
  @ Computational / numerical work: Khavkine CQG(09)-a0809;
    Dittrich & Eckert JPCS(12)-a1111.
  @ Other related topics: Bahr a1812 [non-convex 4D polytopes]; 
    Ansel GRG(21) [open quantum system theory];
    > s.a. black-hole entropy; dimensionality
    of spacetime; FLRW models; graviton;
    linearized quantum gravity [propagator]; quantum
    cosmology.
Other State Sum Models
  @ General features: Barrett gq/00-conf.
  @ Categorical generalizations: Baratin & Wise AIP(09)-a0910 [based on 2-group representations];
    Miković & Vojinović CQG(12)-a1110 [BFCG formulation];
    Miković RVMP(13)-a1302 [spin-cube state sum models, representations of the Poincaré 2-group];
    Miković & Vojinović JPCS(14)-a1512;
    Miković et al CQG(18)-a1807 [BFCG formulation, Hamiltonian analysis].
  @ Cube-based: Baratin et al NJP(12)-a0812 [cubations and Holst action];
    Vojinović PRD(16)-a1506 [spincube models and causal dynamical triangulations].
  @ Other models: Davids gq/01 [Lorentzian, SU(1,1)];
    Pérez ATMP(01)gq/02 [Plebański SO(4) model];
    Miković MPLA(05)gq-conf;
    Bonzom PRD(09)-a0905 [from lattice path integrals];
    Geiller & Noui CQG(12)-a1112 [3D Plebański SO(4) model].
  > Quantum-gravity related:
    see Barrett-Crane Model; Crane-Yetter Model;
    Ponzano-Regge Model; Turaev-Viro Theory.
  > In gauge theory and other theories:
    > see path-integral quantization for gauge theories;
    string theory.
   > Online resources: see Dan
    Christensen's page.
 main page
  – abbreviations
  – journals – comments
  – other sites – acknowledgements
  send feedback and suggestions to bombelli at olemiss.edu – modified 29 apr 2021