Lecture Notes of the Unione Matematica Italiana Ricardo Castano-Bernard Fabrizio Catanese Maxim Kontsevich Tony Pantev Yan Soibelman Ilia Zharkov Editors Homological Mirror Symmetry and Tropical Geometry Lecture Notes of 15 the Unione Matematica Italiana Forfurthervolumes: http://www.springer.com/series/7172 EditorialBoard CiroCiliberto(EditorinChief) CH-8057Zuerich,Switzerland DipartimentodiMatematica e-mail:[email protected] Universita’diRomaTorVergata FrancoFlandoli ViadellaRicercaScientifica DipartimentodiMatematicaApplicata 00133Roma(Italia) UniversitàdiPisa e-mail:[email protected] ViaBuonarroti1c SusannaTerracini(Co-editorinChief) 56127Pisa,Italy UniversitàdegliStudidiTorino e-mail:fl[email protected] DipartimentodiMatematica“GiuseppePeano” AngusMcintyre ViaCarloAlberto10 QueenMaryUniversityofLondon 10123Torino,Italy SchoolofMathematicalSciences e-mail:[email protected] MileEndRoad AdolfoBallester-Bollinches LondonE14NS Departmentd’Àlgebra UnitedKingdom FacultatdeMatemàtiques e-mail:[email protected] UniversitatdeValència GiuseppeMingione Dr.Moliner,50 DipartimentodiMatematicaeInformatica 46100Burjassot(València) UniversitàdegliStudidiParma Spain ParcoAreadelleScienze,53/a(Campus) e-mail:[email protected] 43124Parma,Italy AnnalisaBuffa e-mail:[email protected] IMATI–C.N.R.Pavia MarioPulvirenti ViaFerrata1 DipartimentodiMatematica, 27100Pavia,Italy UniversitàdiRoma“LaSapienza” e-mail:[email protected] P.leA.Moro2 LuciaCaporaso 00185Roma,Italy DipartimentodiMatematica e-mail:[email protected] UniversitàRomaTre FulvioRicci LargoSanLeonardoMurialdo ScuolaNormaleSuperiorediPisa I-00146Roma,Italy PiazzadeiCavalieri7 e-mail:[email protected] 56126Pisa,Italy FabrizioCatanese e-mail:[email protected] MathematischesInstitut ValentinoTosatti Universitätstraße30 NorthwesternUniversity 95447Bayreuth,Germany DepartmentofMathematics e-mail:[email protected] 2033SheridanRoad CorradoDeConcini Evanston,IL60208 DipartimentodiMatematica USA UniversitàdiRoma“LaSapienza” e-mail:[email protected] PiazzaleAldoMoro5 CorinnaUlcigrai 00185Roma,Italy ForschungsinstitutfürMathematik e-mail:[email protected] HGG44.1 CamilloDeLellis Rämistrasse101 InstitutfuerMathematik 8092Zürich,Switzerland UniversitaetZuerich e-mail:[email protected] Winterthurerstrasse190 TheEditorialPolicycanbefoundatthebackofthevolume. Ricardo Castano-Bernard Fabrizio Catanese (cid:2) (cid:2) Maxim Kontsevich Tony Pantev (cid:2) (cid:2) Yan Soibelman Ilia Zharkov (cid:2) Editors Homological Mirror Symmetry and Tropical Geometry 123 Editors RicardoCastano-Bernard FabrizioCatanese MathematicsDepartment MathematischesInstitut KansasStateUniversity UniversitätBayreuth Manhattan,KS,USA Bayreuth,Germany MaximKontsevich TonyPantev InstitutdesHautesEtudesScientifiques MathematicsDepartment Bures-sur-Yvette,France UniversityofPennsylvania Philadelphia,PA,USA YanSoibelman IliaZharkov DepartmentofMathematics KansasStateUniversity Manhattan,KS,USA ISSN1862-9113 ISBN978-3-319-06513-7 ISBN978-3-319-06514-4(eBook) DOI10.1007/978-3-319-06514-4 SpringerChamHeidelbergNewYorkDordrechtLondon LibraryofCongressControlNumber:2014950803 MathematicsSubjectClassification(2010):14J33,53D37,14T05,14N35,14D24 (cid:2)c SpringerInternationalPublishingSwitzerland2014 Thisworkissubjecttocopyright.AllrightsarereservedbythePublisher,whetherthewholeorpartof thematerialisconcerned,specificallytherightsoftranslation,reprinting,reuseofillustrations,recitation, broadcasting,reproductiononmicrofilmsorinanyotherphysicalway,andtransmissionorinformation storageandretrieval,electronicadaptation,computersoftware,orbysimilarordissimilarmethodology nowknownorhereafterdeveloped.Exemptedfromthislegalreservationarebriefexcerptsinconnection with reviews or scholarly analysis or material supplied specifically for the purpose of being entered and executed on a computer system, for exclusive use by the purchaser of the work. Duplication of this publication or parts thereof is permitted only under the provisions of the Copyright Law of the Publisher’slocation,initscurrentversion,andpermissionforusemustalwaysbeobtainedfromSpringer. PermissionsforusemaybeobtainedthroughRightsLinkattheCopyrightClearanceCenter.Violations areliabletoprosecutionundertherespectiveCopyrightLaw. Theuseofgeneraldescriptivenames,registerednames,trademarks,servicemarks,etc.inthispublication doesnotimply,evenintheabsenceofaspecificstatement,thatsuchnamesareexemptfromtherelevant protectivelawsandregulationsandthereforefreeforgeneraluse. While the advice and information in this book are believed to be true and accurate at the date of publication,neithertheauthorsnortheeditorsnorthepublishercanacceptanylegalresponsibilityfor anyerrorsoromissionsthatmaybemade.Thepublishermakesnowarranty,expressorimplied,with respecttothematerialcontainedherein. Printedonacid-freepaper SpringerispartofSpringerScience+BusinessMedia(www.springer.com) Introduction The workshop “Mirror Symmetry and Tropical Geometry” took place in Cetraro, Italy on July 2–8, 2011. The idea was to bring together mathematicians and physicistswhoworkedonbothtopicsorinrelatedareas. HomologicalMirrorSymmetry,hereabbreviatedasHMS,istheareaofmathe- maticsrevolvingaroundseveralcategoricalequivalencesconnectingsymplecticand holomorphic(oralgebraic)geometry.ThismathematicalapproachtoMirrorSym- metrygoesbacktotheworkofMaximKontsevich(1993).Furtherdevelopmentsof Kontsevich’sprogramwasthesubjectofmanytalksattheworkshop.Thisthemeis thereforepresentinseveralpapersofthisvolume. WorksrelatedtoHomologicalMirrorSymmetryincludethepaperonHMSfor Landau–GinzburgmodelsbyH.Ruddat,thepaperofN.SibillaonHMSforcurves, the paper of Kontsevich and Y. Soibelman on complex integrable systems, and the paper by D. Favero, F. Haiden, and L. Katzarkov on the phantom categories which appear in HMS. The variety of methodsrangingfrom homologicalalgebra todelicatequestionsofsymplectictopologyandalgebraicgeometryillustratesthe complexityofthesubject. The second topic of the workshop was Tropical Geometry. Roughly speak- ing, Tropical Geometry studies piecewise-linear objects which appear as certain “degenerations”ofthecorrespondingalgebro-geometricobjects.Therelationshipof TropicalGeometrywithMirrorSymmetrygoesbacktotheworkbyKontsevichand Y. Soibelman (2000)where methodsof non-archimedeangeometry (in particular, tropical curves) were used for the purposes of Homological Mirror Symmetry. Combined with the subsequent work of Mikhalkin on a “tropical” approach to Gromov–Witten theory and with the work of Gross, Siebert, and several others, TropicalGeometryhasbecomeausefultoolforpeopleworkinginMirrorSymme- try. On the other hand, “tropical” analogs of many notions of classical symplectic and algebraic geometry are interesting and nontrivial objects by themselves. The paperbyG.MikhalkinandI.Zharkov,whichisdevotedtothetropicalanalogofthe intermediateJacobian,isa goodillustrationofthisstatement. Methodsoftropical v vi Introduction geometryarealsousedinthepaperbyKontsevichandY.Soibelmandevotedtothe studyofDonaldson–Thomasinvariantsandcorrespondingwall-crossingformulas. The volume also contains several papers which are related to the main topics of the workshop in an indirect way. For example, the paper by S. Guillermou and P. Schapira is devoted to the application of the microlocal theory of sheaves developed by the second author jointly with M. Kashiwara to the displaceability problem in symplectic topology. It should be compared with attempts of several mathematicians to describe the Fukaya category (one of the main objects on the “symplectic” side of Homological Mirror Symmetry) in terms of constructible sheavesandcorrespondingdg-categories. Two papers are devoted to various aspects of the moduli stacks of bundles. In the paper by O. Ben-Bassat and E. Gasparim the stack of vector bundles on a formalneighborhoodofarationalcurveinasurfaceisstudied.InthepaperbyA. Soibelmanthe“verygood”propertyintroducedbyBeilinsonandDrinfeldintheir work on the Geometric LanglandsProgram is generalized to the case of arbitrary parabolic bundles on a curve and then applied to the additive Deligne–Simpson problem. A. Neitzke gives a nice review of his joint work with D. Gaiotto and G. Mooreon the constructionof hyperkählermetrics. Theirapproachisbased onthe thermodynamicalBetheAnsatz-typeintegralequationproposedbythem,aswellas onthe“Kontsevich–Soibelmanwall-crossingformulas”.Therearemanyinteresting andnontrivialanalogiesbetweenthepaperbyNeitzkeandthepaperbyKontsevich andY.Soibelmaninthisvolume. S.GukovandP.Sulkowskiproposeawaytoquantizespectralcurves.Thenthey discuss the relationship of arising “quantum spectral curves” with the topological recursionofEynard–OrantinaswellaswithothertopicssuchasA-polynomialsof knots. The paper by M. Kapranov, O. Schiffmann, and E. Vasserot is devoted to the Hallalgebraofthe“compactifiedSpec.Z/”interpretedasacurve.The“categoryof vectorbundles”onsuchanobjectisdescribedinArakelovterms,asthecategoryof metrizedlattices.The(spherical)Hallalgebraofthiscategoryisashufflealgebra, similar to Hall algebras of the corresponding categories for “usual” curves. The relationsinthealgebraaredescribedintermsforthe(full)zeta-function. Webelievethatthepresentvolumerepresentsarathercompleteupdateaboutthe stateoftheartinthefield,andwehopethatitshallbecomeanimportantreference for graduate students and researchers who want to enter this exciting new field. Papersin thisvolumerepresenta tiny portionof the varietyof topicsdiscussed at the workshop.In order to give to the reader an idea aboutthe latter we finish the IntroductionwiththelistoftalkspresentedattheCetraroworkshop. Introduction vii Acknowledgement ofSupport ThisprojectwaspartiallysupportedbytheNSFFocusResearchGroupawardDMS- 0854989“MirrorSymmetryandTropicalGeometry”. Lectures (cid:129) Mina Aganagic(Berkeley):KnotHomologyfromRefined Chern–SimonsThe- ory. (cid:129) Fedor Bogomolov (NYU): On rationality of the fields of invariants of linear actionsforconnectednonsemisimplealgebraicgroups(basedonmyjointwork withChristianBoehningandHans-ChristianGrafvonBohtmer). (cid:129) Fabrizio Catanese (Bayreuth):Special Galois coveringsand the singular set of themodulispaceofcurves (cid:129) Alexander Efimov (Steklov Institute): Cohomological Hall algebra and Kac’s conjecture (cid:129) Vladimir Fock (Strasbourg): Integrable systems, dimers and cluster varieties. (JointworkwithAMarshakov) (cid:129) KenjiFukaya(Kyoto):HomologicalMirrorsymmetryoftoricmanifolds (cid:129) AlexanderGoncharov(Yale):Dimersandclusterintegrability (cid:129) MarkGross(UCSD):Examplesofstablelogmapsandtropicalgeometry (cid:129) Sergei Gukov (Caltech): From hyperholomorphic sheaves to quantum group invariantsviaLanglandsduality (cid:129) IliaItenberg(Strasbourg):Topologyofrealtropicalhypersurfaces (cid:129) MikhailKapranov(Yale):ArithmeticHallalgebras (cid:129) LudmilKatzarkov(MiamiandVienna):Degenerationsandwallcrossings (cid:129) Viatcheslav Kharlamov (Strasbourg): Anti-symplectic involutions on rational symplectic4-manifolds (cid:129) MaximKontsevich(IHES):Integrablesystemsandcanonicalbases (cid:129) AndreiLosev(ITEP):Homotopicalbeta-functionoftheinstantonicsigma-model andbosonicstringEinsteinequationonschemes (cid:129) DiegoMatessi(UofMilan):Conifoldtransitionsandtropicalgeometry (cid:129) David Morrison (UCSB): Mirror symmetry and non-complete-intersection Calabi–Yaumanifolds (cid:129) AndyNeitzke(UTAustin):A2d-4dwall-crossingformula (cid:129) NikitaNekrasov(IHES):SurpriseswithfourdimensionalND2gaugetheories (cid:129) DimitriOrlov(Steklov):Mirrorsymmetry,B-branesandstrangeArnoldduality (cid:129) TonyPantev(UPenn):MirrorsymmetryandmixedHodgestructures ix