Celebratio Mathematica

Per­son­al data

Wal­ter Dav­id Neu­mann, born 01/01/1946 in Caerphilly, Wales, UK; U.S. cit­izen.

Edu­ca­tion

Ex­per­i­ence in high­er edu­ca­tion

Per­man­ent po­s­i­tions

Vis­it­ing po­s­i­tions (teach­ing & re­search)

Vis­it­ing re­search po­s­i­tions

Hon­or­ary ap­point­ments

Hon­ors

Mem­ber­ship of pro­fes­sion­al so­ci­et­ies

Amer­ic­an As­so­ci­ation for the Ad­vance­ment of Sci­ence (AAAS)
Amer­ic­an Math. So­ci­ety
As­so­ci­ation for Wo­men in Math­em­at­ics
Aus­trali­an Math. So­ci­ety
European Math. So­ci­ety
Société Mathématique de France

Re­search

Re­search area

Geo­metry/To­po­logy: Geo­met­ric Group The­ory, Geo­met­ric To­po­logy, Al­geb­ra­ic Geo­metry

Re­search grants

• “3-man­i­folds and geo­metry”, NSF, 2009–2012, 2012–2016, 2016–2019
• “New tech­niques in low-di­men­sion­al to­po­logy and geo­metry”, NSF Re­search Train­ing Grant, 2008–2013 (with Khovan­ov, Mor­gan, Oz­sváth)
• “3-man­i­folds, sin­gu­lar­it­ies, and in­vari­ants”, NSF, 2005–2007, 2007–2009
• “Abeli­an Galois ex­ten­sions as com­plete in­ter­sec­tions”, NSA, 2006–2008
• “Col­lab­or­at­ive Re­search: FRG: Hy­per­bol­ic Geo­metry and Jones Poly­no­mi­als”, NSF, 2005–2008
• “In­vari­ants of 3-man­i­folds and their ap­plic­a­tions”, NSF, 2002–2005
• “3-man­i­folds and their ap­plic­a­tions to geo­metry” NSF, 2000–2002
• Con­tinu­ous re­search sup­port, Aus­trali­an Re­search Coun­cil, 1993–2000
• Con­tinu­ous re­search sup­port, NSF, 1976–1993

High­er de­gree su­per­vi­sion

PhD stu­dents

• Har­old Sul­tan “The asymp­tot­ic cone of Teich­muller space: Thick­ness and di­ver­gence”, May 2012 (co-su­per­visor: Jason Behr­stock)
• Helge Møller Ped­er­sen, “Splice dia­grams, sin­gu­lar­ity links and uni­ver­sal abeli­an cov­ers”, May 2009
• Chris­ti­an Zick­ert, “Hy­per­bol­ic man­i­folds and the Chee­ger–Chern–Si­mons class”, May 2008
• Philip Or­d­ing, “On knot Flo­er ho­mo­logy of satel­lite \( (1,1) \)-knots”, May 2006
• P. J. Lam­ber­son, “Splice type sin­gu­lar­it­ies and it­er­ated branched cyc­lic cov­ers”, May 2006
• Har­riet Moser, “Prov­ing a man­i­fold to be hy­per­bol­ic once it has been ap­prox­im­ated to be so”, Dec 2004
• Ab­hijit Cham­pan­erkar, “A-poly­no­mi­al and Bloch in­vari­ants of 3-man­i­folds”, 2003
• P. Wightwick, “To­po­logy of Af­fine Al­geb­ra­ic Plane Curves”, 2002
• S. Till­mann, “Sur­faces as­so­ci­ated to muta­tion and de­form­a­tion of hy­per­bol­ic 3-man­i­folds”, 2002 (co-su­per­visor: C. Hodg­son)
• M. Eld­er, “Auto­mati­city, al­most con­vex­ity, and falsi­fic­a­tion by fel­low trav­el­ler prop­er­ties of some fi­nitely gen­er­ated groups”, 2000
• A. Di­Pasquale, “Links and Com­ple­ments of Plane Curves”, 1999
• M. Ouyang, “Eta-in­vari­ants of geo­met­ric 3-man­i­folds”, 1992
• L. Christine Kin­sey, “Pseu­doiso­top­ies and Sub­mer­sions of a Com­pact Man­i­fold to the Circle”, 1984 (co-su­per­visor: H. King)
• M. Jankins, “The space of ho­mo­morph­isms of a Fuch­sian group to \( P \operatorname{SL}(2, R) \)”, 1983
• N. Duch­on, “In­vol­u­tions of plumbed man­i­folds”, 1982
• D. Bern­stein, “New­ton poly­hedra and co­homo­logy of com­plete in­ter­sec­tions”, 1982
• K. H. Knapp, “Sig­na­turde­fekte mod­ulo \( \mathbf{Z} \) für freie G-Ak­tion­en”, 1975 (first su­per­visor: F. Hirzebruch)
• A. Scharf, “Faser­ungen von Graphen­man­nig­faltigkeiten”, 1973 (first su­per­visor: F. Hirzebruch)

Oth­er

• M.A.: P. Wightwick, ”Sin­gu­lar­it­ies of Plane Curves”, 1995
• Dip­lom: W. Hey­mans, “Klas­si­fika­tion der Auto­morph­is­men von Flächen und Voll­brezeln”, 1975
• Dip­lom: N. Ryska, “Bet­tizah­len von Open Books”, 1975
• Dip­lom: C. P. Fit­ting, “Faser­ungen von Graphen­man­nig­faltigkeiten”, 1975
• Dip­lom: C. Olk, “Die Sin­guläre Ho­mo­lo­gi­e­th­e­or­ie mit geschlossenem Träger”, 1975
• Dip­lom: R. Bo­hm, “Or­biträuume abelscher G-Ak­tion­en”, 1974

Thes­is de­fense com­mit­tees (since 2000: Columbia Uni­versity un­less oth­er­wise noted)

• 2020: Ren­ato Oli­veira Tar­gino (Uni­ver­sid­ade Fed­er­al do Ceará) (Feb­ru­ary)
• 2017: Rochy Flint (CUNY Gradu­ate Cen­ter)
• 2015: Roberto Cas­tellini (Uni­versité Lille), Thes­is Ref­er­ee (Ju­ly) and Thes­is Jury (Sept)
• 2014: Cor­rin Clark­son, Jonath­an Hansel­man
• 2013: Kristen Hendricks
• 2012: Ha­bil­it­a­tion: Pierre Der­bez (Centre de Mathématiques et In­form­atique, Uni­versité de Provence)
• 2012: Har­old Sul­tan, Ina Petkova, Irena Penev
• 2011: Haydée Aguilar Cab­rera (Uni­ver­sid­ad Nacion­al Autónoma de México, Cuerna­vaca); Thes­is Jury (Mar) and De­fense Com­mit­tee (April)
• 2009: Helge Møller Ped­er­sen
• 2008: Eric Sim­ring, Chris­ti­an Zick­ert
• 2007: Yang Su (Heidel­berg Uni­versity)
• 2006 Ha­bil­it­a­tions: Anne Pichon (In­sti­tut de Mathématiques de Lu­miny) Héléne Mau­gendre (Uni­versity of Gren­oble)
• 2006: Jeff Phan, PJ Lam­ber­son, Phil Or­d­ing, Keiko Kamu­muro
• 2005: Sally Kuhl­man (Mel­bourne)
• 2004: H. Moser, A. McIn­roy
• 2003: N. Broad­dus, A. Cham­pan­erkar
• 2002: N. Wrinkle, T. Brendle, C. Lein­inger (Aus­tin TX), D. Ci­m­a­soni (Geneva) Thes­is Ref­er­ee and Thes­is Jury
• 2001: M. Zinno, G. Rosen­berg, R. Popes­cu, G. Lang­mead, D. Re­becci (Rut­gers Ne­wark)

Postdoc su­per­vi­sions (since 2000)

• Nick Salt­er, Fall 2018–
• Bog­Wang Jeon, Fall 2013–2017
• Mur­at Savas, Fall 2012–Spring 2014
• Haydée Aguilar Cab­rera, Spring 2012–Spring 2013
• Xiaobo Liu, Fall 2005–Spring 2009
• Chris Lein­inger, Fall 2002–Spring 2005

Un­der­gradu­ate re­search su­per­vi­sion (since 2000)

• Su­per­vised re­search Ran­keya Datta, Sum­mer, 2012
• Seni­or thes­is Mi­chael Lim, Spring 2007
• Seni­or thes­is “Com­plex re­flec­tion groups in di­men­sion 2”, Neeraj Pra­dhan, 2005–06
• Seni­or thes­is and sum­mer pro­ject “A math­em­at­ic­al mod­el of cel­lu­lar ap­op­tos­is through dy­nam­ics of te­lomere loss”, Nat­alie Arkus, Spring/Sum­mer 2003, ap­peared 2005 in J. The­or­et­ic­al Biol. (cited as num­ber 4 among the top 25 pa­pers in Ag­ri­cul­tur­al and Bio­lo­gic­al Sci­ences in 2005 by Sci­en­ce­dir­ect.com)
• Re­search pro­ject on com­pu­ta­tion of Di­rich­let do­mains, Max Lipyanskiy, Fall 2001/Spring 2002
• Vi­gre Sum­mer Re­search Pro­ject on ex­cep­tion­al 3-man­i­folds, Jac­ob Lewis, Max Lipyanskiy, Scott Meltzer, Sum­mer 2001, pub­lished in Ex­per. Math.
• Hon­ours thes­is: Re­search pro­ject on A-poly­no­mi­al, J. Bueti, Spring semester 2001
• Re­search Pro­ject on cusp sin­gu­lar­it­ies, D. An­der­son, Spring semester 2001, pub­lished as “A cusp sin­gu­lar­ity with no Galois cov­er by a com­plete in­ter­sec­tion” Proc. AMS, 2004
• Vi­gre Sum­mer Re­search Pro­ject on A-poly­no­mi­al, J. Bueti, P. Or­d­ing, A. Stern, Sum­mer 2000

De­part­ment and uni­versity ad­min­is­tra­tion (since 2000)

• Ex­ec­ut­ive Com­mit­tee, Columbia Univ. Math. Dept., 2000–
• Fac­ulty rep­res­ent­at­ive for Barn­ard/Columbia chapter of Gamma Iota Sigma (Risk Man­age­ment, In­sur­ance and Ac­tu­ar­ial Sci­ence ma­jors) un­til 2018.
• Un­der­gradu­ate Com­mit­tee, (Chair Fall 2010) 2004–2019
• Columbia Math­em­at­ics Lib­rary Com­mit­tee, 2004–06, 2007–19
• Ad­vis­ory Board, Barn­ard Cen­ter for Re­search on Wo­men, 2000–
• Kol­chin and Ritt Lec­tures Com­mit­tee, 2002–04, 2006–07, 2008–2017
• Cal­cu­lus II dir­ect­or, 2014–2015
• Barn­ard Com­mit­tee on Hon­ors, Fall 2013–2015
• Chair, Barn­ard De­part­ment of Math­em­at­ics, 2000–04, 2005–06, 2011–2015
• Barn­ard Lib­rary and Aca­dem­ic In­form­a­tion Ser­vice Com­mit­tee, Fall 2009–Fall 2010
• Barn­ard Com­mit­tee on Pro­grams and Aca­dem­ic Stand­ing, Fall 2007
• Chair, Prize Ex­am Com­mit­tee, 2000, 2001–04 and 2005–07
• Cal­cu­lus Dir­ect­or, Barn­ard/Columbia, 2005–07
• Chair, Helen Kim­mel Chair Search Com­mit­tee, 2006
• Cal­cu­lus 3 Cap­tain, Fall 2004
• PI for un­der­gradu­ate af­fairs for the Math Dept Vi­gre grant, Fall 2001–2004
• Ju­ni­or Hir­ing Com­mit­tee, Columbia, 2005/06/07
• Chair, Columbia Math Dept Ju­ni­or Hir­ing Com­mit­tee 2001
• Barn­ard Com­mit­tee on In­struc­tion, Fall 2001–Spring 2002
• Barn­ard Grants Com­mit­tee, Fall 2000–Spring 2002
• Barn­ard ATP Com­mit­tee (mem­ber at large), Fall 2000–Spring 2002

Oth­er pro­fes­sion­al activ­it­ies, com­munity re­la­tions

Cur­rent ed­it­or­ships, re­search journ­als

• Ed­it­or­i­al board, Geo­metry & To­po­logy, since 1996 (Man­aging Ed­it­or, 2005–2012)
• To­po­logy/Geo­metry ed­it­or, Illinois J. Math. 2008–
• Ed­it­or­i­al board, Ex­per­i­ment­al Math­em­at­ics, (A.K. Peters), 1996–
• Ed­it­or­i­al board, Elec­tron­ic Re­search An­nounce­ments in the Math­em­at­ic­al Sci­ences, 2007–

Cur­rent ed­it­or­ships, mono­graph series

• Ed­it­or­i­al Board, Ohio State Univ. Math. Re­search In­sti­tute Pub­lic­a­tions (de Gruyter), 1990–
• Ed­it­or­i­al Board, de Gruyter Ex­pos­i­tions in Math­em­at­ics, 1987–

Pre­vi­ous ed­it­or­ships

• Con­sult­ing Ed­it­or, Pro­ceed­ings Ed­in­burgh Maths. Soc., 1998–2015
• Ed­it­or­i­al Board, Trans­form­a­tion Groups (Birkhäuser Ver­lag), 1995–2007
• Ed­it­or­i­al Board, Elec­tron­ic Re­search An­nounce­ments of the Amer. Math. Soc., 1995–2007
• As­so­ci­ate Ed­it­or, Journ­al of the Aus­trali­an Math. Soc., 1998–99
• Ed­it­or­i­al Board, Aus­trali­an Math. Soc. Lec­ture Series (Cam­bridge Univ. Press), 1996–2000
• To­po­logy Ed­it­or, Trans­ac­tions of the Amer. Math. Soc., 1982–85
• To­po­logy Ed­it­or, Mem­oirs of the Amer. Math. Soc., 1982–85

Con­fer­ence Grants awar­ded (since 2000), in­cl. size, fund­ing agency, or­gan­izers

• Work­shop “Lipschitz Geo­metry of Sin­gu­lar­it­ies”, Casa Matemática Oax­aca, Mex­ico, Oc­to­ber 2018; 42 par­ti­cipants; BIRS/CMO; Neu­mann, Pichon, Snoussi.
• Work­shop “Low-di­men­sion­al to­po­logy and num­ber the­ory”, Ober­wolfach, Ger­many, Au­gust 2017; 48 par­ti­cipants; MFO; Gun­nells, Neu­mann, Sikora, Za­gi­er.
• Work­shop “To­po­lo­gic­al meth­ods in sin­gu­lar­ity the­ory”, Ed­in­burgh, UK, 2015; ap­prox. 50 par­ti­cipants; ICMS; Borodzig, Neu­mann, Pichon, Ran­icki. Fund­ing for US par­ti­cipants; NSF; Neu­mann.
• Petits groupes de trav­ail “Lipschitz Geo­metry of func­tion germs \( \mathbb{C}^2 \to \mathbb{C} \)”; Lu­miny, France; 01/12/2015–01/16/2015, CIRM; par­ti­cipants: Neu­mann, Pichon, Teis­si­er.
• Work­shop “Low-di­men­sion­al to­po­logy and num­ber the­ory” Ober­wolfach, Ger­many, Au­gust 2014; 48 par­ti­cipants; MFO; Gun­nells, Neu­mann, Sikora, Za­gi­er.
• Petits groupes de trav­ail “Lipschitz Geo­metry of func­tion germs \( \mathbb{C}^2 \to \mathbb{C} \)”; Lu­miny, France; 06/01/2014–06/13/2014; CIRM; par­ti­cipants: Gaffney, Neu­mann, Pichon, Teis­si­er.
• Work­shop “Low-di­men­sion­al to­po­logy and num­ber the­ory”, Ober­wolfach, Ger­many, Au­gust 2012; 48 par­ti­cipants; MFO; Gun­nells, Neu­mann, Sikora, Za­gi­er.
• Petits groupes de trav­ail “Géométrie bilipschitz des es­paces ana­lytiques com­plexes”; Lu­miny, France; 05/14/2012–05/25/2012; CIRM; par­ti­cipants: Birbrair, Neu­mann, Pichon.
• Work­shop “Low-di­men­sion­al to­po­logy and num­ber the­ory”, Ober­wolfach, Ger­many, Au­gust 2010; 48 par­ti­cipants; MFO; Gun­nells, Neu­mann, Sikora, Za­gi­er.
• Work­shop “Ri­gid­ity in To­po­logy”, Ban­ff, March 2010; 20 par­ti­cipants; BIRS; Behr­stock, Ka­povitch, Neu­mann.
• Re­search in pairs, Lu­miny, France (2 weeks Jun/Jul 2009); CIRM; Birbrair, Neu­mann, Pichon.
• Work­shop “Low-di­men­sion­al to­po­logy and num­ber the­ory”, Ban­ff, Oct 2007; 40 par­ti­cipants; BIRS; Boyd, Gun­nells, Neu­mann, Sikora.
• Con­fer­ence in hon­or of Joan Birman, “Braids, Links and Map­ping Class Groups”, Barn­ard/Columbia, March 2005; 108 par­ti­cipants; NSF; Behr­stock, Kof­man, Lein­inger, Neu­mann.

Oth­er con­fer­ence com­mit­tees (since 2000)

• Co-or­gan­izer, In­ter­na­tion­al School on Sin­gu­lar­it­ies and Lipschitz Geo­metry, Cuerna­vaca, Mex­ico, June 2018
• Co-or­gan­izer, Con­fer­ence “To­po­lo­gic­al and Quant­it­at­ive As­pects of Sym­plect­ic Man­i­folds”, Barn­ard/Columbia, March 17–20 2016
• Sci­entif­ic Com­mit­tee, “10th Mini­Work­shop, Sin­gu­lar­it­ies, Geo­metry and Dif­fer­en­tial Equa­tions”, Fortaleza, Brazil, May 2015
• Co-or­gan­izer, Con­fer­ence “In­vari­ants in Low Di­men­sion­al Geo­metry”,

  Gazi Uni­ver­stity, Ank­ara, Au­gust 10–14 2015

• Co-or­gan­izer, ICERM Semester pro­gram: “Low Di­men­sion­al To­po­logy, Geo­metry and Dy­nam­ics”, Brown Uni­versity, Fall 2013
• Co-or­gan­izer, In­ter­na­tion­al con­fer­ence “Geo­met­ric To­po­logy in New York”, Au­gust 2013 (NSF fun­ded)
• Co-or­gan­izer, Spe­cial Ses­sion on Geo­metry and Sin­gu­lar­it­ies, AMS Re­gion­al Meet­ing, Worcester MA, April 2011
• Sci­entif­ic Com­mit­tee, “The XI Work­shop on Real and Com­plex Sin­gu­lar­it­ies” São Car­los, Brazil, Ju­ly 2010
• Chair of or­gan­iz­ing com­mit­tee, gradu­ate work­shop and in­ter­na­tion­al con­fer­ence “In­ter­ac­tions between Hy­per­bol­ic Geo­metry, Quantum To­po­logy and Num­ber The­ory”, Columbia Uni­versity, Jul 2–20 2009
• Co-Or­gan­izer, In­ter­na­tion­al con­fer­ence “A second time around the Volume Con­jec­ture”, Bat­on Rouge, May 2007
• Chair of or­gan­iz­ing com­mit­tee, In­ter­na­tion­al con­fer­ence “Around the Volume Con­jec­ture”, Barn­ard/ Columbia, March 2006
• Co-or­gan­izer, In­ter­na­tion­al work­shop “Soft­ware for the Work­ing Math­em­atician”, CUNY, May 2003
• Co-or­gan­izer, Spe­cial Ses­sion on To­po­lo­gic­al Meth­ods in Com­plex Sin­gu­lar­it­ies, AMS Re­gion­al Meet­ing, New York Uni­versity, April 2003
• Co-or­gan­izer, Spe­cial Ses­sion on To­po­logy of 3-Man­i­folds (\( + \) pre-meet­ing work­shop), AMS Meet­ing 959, New York, Nov. 2000

Re­view­ing and ref­er­ee­ing (since 2000)

• Ref­er­ee­ing re­search pro­pos­als for the NSF, NSA, Si­mons Found­a­tion, Ca­na­dian Re­search Coun­cil, Aus­trali­an Re­search Coun­cil, Eng­lish EPSRC, Swiss NSF, Geor­gi­an NSF, In­di­an Academy of Sci­ences, French Na­tion­al Re­search Agency, et al.
• Ref­er­ee­ing for many math. journ­als
• NSF re­view pan­els, Nov 2003, Feb 2006, Feb 2008, Oct 2009
• “Pan­el of ex­perts” French Na­tion­al Re­search Agency (ANR) 2006–2007, 2009–
• Geor­gi­an Na­tion­al Sci­ence Found­a­tion re­gistered peer re­view­er 2007–
• Col­lege of Re­view­ers, Canada Re­search Chairs Pro­gram, 2003–

Com­munity (since 2000)

• Math for Amer­ica New­ton Fel­low­ship Screen­ing and Se­lec­tion Com­mit­tee 2007, 2008
• Com­mit­tee on Hu­man Rights, New York Acad. Sci. 2005–2011
• Mem­ber of Board: Com­mit­tee of Con­cerned Sci­ent­ists, 2004–

Ad­min­is­trat­ive (since 2000)

• Board of Dir­ect­ors and Steer­ing Com­mit­tee: Math­em­at­ic­al Sci­ences Pub­lish­ers, 2005–2017, emer­it­us 2017–
• Board mem­ber: New Zea­l­and Math­em­at­ics Re­search In­sti­tute Inc., 1997–
• Ex­ec­ut­ive Com­mit­tee: Geo­metry & To­po­logy Pub­lic­a­tions, 2005–2017
• Ed­it­or­i­al Boards Com­mit­tee of the Amer­ic­an Math­em­at­ic­al So­ci­ety 2013–15 (chair 2015)
• Com­mit­tee on Pub­lic­a­tions, Amer­ic­an Math­em­at­ic­al So­ci­ety, 2013, 2015
• Aus­trali­an Math. Soc. Medal Com­mit­tee, 1998–2000

In­ter­na­tion­al lec­ture courses (re­cent)

• Lec­ture course (3 hours), In­ter­na­tion­al School on Sin­gu­lar­it­ies and Lipschitz Geo­metry, Cuerna­vaca, Mex­ico, June 2018
• Lec­ture course (3 hours), “Lipschitz geo­metry of sin­gu­lar­it­ies”, Frun­am, Mar­seille, France, Novem­ber 2017
• Lec­ture course (4 hours), “Lipschitz geo­metry of sin­gu­lar­it­ies”, Banach Cen­ter, Be­dle­wo, Po­land, Au­gust 2017
• Lec­ture course (5 hours), “Quasi-iso­met­ric clas­si­fic­a­tion of 3-man­i­fold groups”, Toulouse Uni­versity, 3–7 Ju­ly 2017
• Lec­ture course (4 hours), GDR con­fer­ence “Géométrie et to­po­lo­gie des sin­gu­lar­ité com­plexes”, CIRM, Lu­miny, France, April 2013
• Lec­ture course (4 hours, with A. Pichon), Work­shop on “The To­po­logy of Al­geb­ra­ic Vari­et­ies”, CRM Montreal, Septem­ber 2012
• Lec­ture course (5 \( \times \) 75 min), Winter School “Geo­metry & To­po­logy Down Un­der”, Mel­bourne Uni­versity, Ju­ly 2011
• Lec­ture course (4 hours), Hy­per­bol­ic geo­metry: al­gorithmic, num­ber the­or­et­ic and nu­mer­ic­al as­pects, Korea In­stute of Ad­vanced Stud­ies, Seoul, March 2010
• Lec­ture course (3 hours), In­ter­ac­tions between hy­per­bol­ic geo­metry, quantum to­po­logy and num­ber the­ory, Columbia Uni­versity, Ju­ly 2009
• Lec­ture series (5 lec­tures), “Le­Fest: School and work­shop on the to­po­logy and geo­metry of sin­gu­lar­it­ies,” Cuerna­vaca, Mex­ico, Jan 2007
• Lec­ture series for gradu­ate stu­dents (7 lec­tures), Tokyo Inst. Tech., Jul–Aug 2006
• Lec­ture course (2 hours \( + \) tu­tori­als), ICTP Trieste, Au­gust 2005
• Lec­ture course (3 hours), Sin­gu­lar­it­ies work­shop for young re­search­ers, CIRM, Feb 2005

In­vited lec­tures (re­cent)

• “Ele­ment­ary the­ory of groups and group rings, in memory of Gil­bert Baumslag” Novem­ber 1–2 2018 at Fair­field Uni­versity and CUNY gradu­ate cen­ter
• First speak­er at “The Fourth Duke Math­em­at­ic­al Journ­al Con­fer­ence”, Apr 26–29 2018
• Fi­nal speak­er at “Day of Sin­gu­lar­it­ies at North­east­ern Uni­versity”, Apr 20, 2018 Hirzebruch Col­loqui­um, Max-Planck-In­sti­tut für Math, Bonn, Ger­many, Nov 13, 2017
• In­vited Lec­ture (can­celled), MCA-2017, Ses­sion “Quant­it­at­ive Geo­metry”, Montreal, Ju­ly 24–28, 2017
• To­po­logy Sem­in­ar, CUNY Gradu­ate Cen­ter, March 28, 2017
• Plen­ary Lec­ture (sub­sti­tut­ing for Anne Pichon) at “A Pan­or­ama on Sin­gu­lar Vari­et­ies; A Con­fer­ence to Cel­eb­rate Lê Düng Tráng’s 70th Birth­day”, Seville, Feb 10, 2017
• Col­loqui­um lec­ture, Rut­gers, Ne­wark, Dec 13, 2016
• Col­loqui­um lec­ture, Mar­seille, Nov 4, 2016
• Sin­gu­lar­it­ies, Math­em­at­isches Forschungsin­sti­tut Ober­wolfach, Sept 25, 2016 14th In­ter­na­tion­al Work­shop on Real and Com­plex Sin­gu­lar­it­ies, São Car­los, Brazil, Ju­ly 2016
• Sem­in­ar, Fortaleza, Brasil, Ju­ly 2016
• Sem­in­ar, Mar­seille Uni­versity, June 2016
• Mem­bers Sem­in­ar, In­sti­tute for Ad­vanced Study, Feb 2016
• Sem­in­ar, Uni­versity of Lille, France, Septem­ber 2015
• Lec­ture, Work­shop “Sin­gu­lar­ity The­ory in Fortaleza”, Brasil, May 2015
• Plen­ary lec­ture, Con­fer­ence on “Geo­metry of Sin­gu­lar Spaces and Maps”, CIRM, Lu­miny, March 2015
• Plen­ary lec­ture, Con­fer­ence on “Sin­gu­lar­it­ies in geo­metry, to­po­logy, fo­li­ations and dy­nam­ics”, Me­rida, Mex­ico, Dec 2014
• To­po­logy Sem­in­ar, Prin­ceton Uni­versity, Nov 2014
• PATCH Sem­in­ar, Temple Uni­versity, Sept 2014
• Sem­in­ar, CUNY Gradu­ate Cen­ter, May 2014
• Plen­ary lec­ture, GEAR (GEo­met­ric struc­tures And Rep­res­ent­a­tion vari­et­ies), Univ. of Mary­land, March 2014
• SUSI work­shop, Uni­versité de Lille, France, Janu­ary 2014
• Sem­in­ar, North­east­ern Uni­versity, Novem­ber 2013
• Col­loqui­um, Uni­versity of Michigan, Oc­to­ber 2013
• Ses­sion on Sin­gu­lar­it­ies, 1st Math­em­at­ic­al Con­gress of the Amer­icas, Guanajuato, Mex­ico, Au­gust 2013
• Bran­de­is/Har­vard/MIT Col­loqui­um, Bran­de­is, Feb­ru­ary 2013
• Spe­cial ses­sion on aca­dem­ic pub­lish­ing, Amer. Math. Soc. AGM, San Diego, Jan 2013
• Plen­ary Lec­ture, Con­fer­ence “Arnold-75”, Steklov In­sti­tute, Mo­scow, Decem­ber 2012
• Me­mori­al Col­loqui­um for Friedrich Hirzebruch, MPIM Bonn, Oc­to­ber 2012
• 12th In­ter­na­tion­al Work­shop on Real and Com­plex Sin­gu­lar­it­ies, São Car­los, Brazil, Ju­ly 2012
• Plen­ary lec­ture, Con­fer­ence “Sin­gu­lar­ity the­ory, its mod­ern ap­plic­a­tions and fu­ture pro­spects,” Liv­er­pool, June 2012
• Sem­in­ar, Uni­versity of Mar­seille, May 2012
• Plen­ary lec­ture, 50th Cor­nell To­po­logy Fest­iv­al, May 2012
• Lunch Sem­in­ar and Geo­metry Sem­in­ar, PSU, Feb 2012
• Plen­ary Lec­ture, Con­fer­ence “Res­ol­u­tion of Sin­gu­lar­it­ies and Re­lated Top­ics” in hon­or of the 80th birth­day of Heisuke Hironaka, Tordesil­las, Spain, Sep 2011
• Plen­ary Lec­ture, “Geo­metry & To­po­logy Down Un­der” (Con­fer­ence in hon­our of Hyam Ru­bin­stein), Mel­bourne Uni­versity, Ju­ly 2011
• Spe­cial sem­in­ar, Ja­gi­el­lo­ni­an Uni­versity, Cra­cow, Po­land, May 2011
• Plen­ary lec­ture, “Work­shop on Sin­gu­lar­it­ies in Geo­metry and Ap­plic­a­tions”, IM­PAS Banach Cen­ter, Be­dle­wo, Po­land, May 2011
• Sem­in­ar, Uni­versité de Provence Aix-Mar­seille I, May 1, 2011
• Plen­ary Ad­dress, East­ern Sect. AMS Meet­ing, Worcester, MA Apr 2011
• In­vited 45-minute lec­ture, Spe­cial Ses­sion “Num­ber The­ory, Arith­met­ic To­po­logy, and Arith­met­ic Dy­nam­ics”, East­ern Sect. AMS Meet­ing, Worcester, MA Apr 2011
• Col­loqui­um, UN­AM, Cuerna­vaca, Mex­ico, Apr 2011
• In­vited Ad­dress, Con­fer­ence “Fi­nitely Presen­ted Solv­able Groups” CUNY, Mar 2011
• Rut­gers/IAS/Penn “Ap­plic­a­tions of To­po­lo­gic­al Ideas” sem­in­ar, Rut­gers, Feb 2011
• To­po­logy Sem­in­ar, Chica­go Uni­versity, Nov 2010
• Col­loqui­um, Temple Uni­versity, Oct 2010
• Low-di­men­sion­al to­po­logy and num­ber the­ory, MFO, Ger­many, Aug 2010
• Plen­ary lec­ture, 11th In­ter­na­tion­al Work­shop on Sin­gu­lar­it­ies, São Car­los, Brazil, Jul 2010
• Sem­in­ar, Fed­er­al Uni­versity of Ceará, Brasil, Ju­ly 2010
• Quantum Geo­metry and To­po­logy, CIRM, Lu­miny, France, Ju­ly 2010
• Eighth Joint In­ter­na­tion­al Meet­ing of the AMS and the So­ciedad Matemática Mex­ic­ana, Spe­cial Ses­sion on Sin­gu­lar­ity The­ory and Al­geb­ra­ic Geo­metry, June 2010
• To­po­logy Sem­in­ar, Bo­ston Col­lege, April 2010
• BIRS work­shop “Ri­gid­ity in To­po­logy,” Ban­ff, March 2010
• New Dir­ec­tions in Geo­met­ric Group The­ory, Bris­bane, Aus­tralia, Dec 2009
• Man­hat­tan Group The­ory Day, CUNY, NY, Dec 2009
• Wil­li­am Row­an Hamilton Geo­metry and To­po­logy Work­shop, Dub­lin, Sep 2009
• BHN Day, Group The­ory con­fer­ence, Bath, Eng­land, Au­gust 2009
• In­vited lec­ture, “Lib60ber: To­po­logy of Al­geb­ra­ic Var­it­ies, A Con­fer­ence in Hon­or of the 60th Birth­day of Anato­ly Libgober”, Jaca, Spain, June 2009
• To­po­logy Sem­in­ar, War­wick Uni­versity, April 2009
• To­po­logy Sem­in­ar, MPIM Bonn, April 2009
• Lec­ture for the 6-year re­view of Max-Planck-In­sti­tut für Math, Bonn, March 2009
• Work­shop “Low Di­men­sion­al To­po­logy and Num­ber The­ory”, Fukuota, Ja­pan, Mar 2009
• Geo­metry Sem­in­ar, Ox­ford Uni­versity, Mar 2009
• Plen­ary lec­ture, 10th In­ter­na­tion­al Work­shop on Sin­gu­lar­it­ies, São Car­los, Brazil, Jul 2008
• Sem­in­ar, Uni­versité de Provence Aix-Mar­seille I, Jun 2008
• “Af­fine Geo­metry, Num­ber The­ory and Sin­gu­lar­it­ies in Hon­or of Pier­rette Cas­sou-Nogues”, CIEM, Can­tab­ria, Spain, June 16–20, 2008
• Plen­ary lec­ture, Con­fer­ence “Al­geb­ra­ic and geo­met­ric to­po­logy,” Gdansk, June 9–13, 2008
• AMS Spe­cial Ses­sion, Bat­on Rouge, March 29, 2008
• BIRS work­shop “To­po­logy and Num­ber The­ory”, Ban­ff, Oct 2007
• CUNY group the­ory sem­in­ar, Oct 2007
• IV Con­gresso Iberoamer­icano de Geo­metria Com­pl­exa, Ouro Preto, Brasil, Au­gust 2007
• Con­fer­ence “Hy­per­bol­ic struc­tures on 3-man­i­folds and the large scale geo­metry of Teichmüller space”, War­wick, Ju­ly 2007
• Bonn Arbeit­sta­gung (50 year Ju­biläum), Max-Planck-In­sti­tut für Math., Bonn, June 2007
• AIM Work­shop on Geo­met­ric Group The­ory, Apr, 2007
• Col­loqui­um and Sem­in­ar, Ok­lahoma State Uni­versity, Apr 2007
• RTG lec­ture and To­po­logy sem­in­ar, MSU, Apr 2007
• Col­loqui­um, Brown Uni­versity, Mar 2007
• To­po­logy Sem­in­ar, UT Aus­tin, Nov 2006
• Col­loqui­um and Sem­in­ar, UNC Chapel Hill, Oct 2006
• Con­fer­ence “Poly­no­mi­al Auto­morph­isms and re­lated top­ics”, Hanoi, Vi­et­nam, Oct 2006
• 3-Man­i­folds con­fer­ence, Ober­wolfach, Sep 2006
• Con­fer­ence ILDT2006, Hiroshi­ma, Ju­ly 2006
• Col­loqui­um and To­po­logy sem­inars, (5 lec­tures) Tokyo Inst. Tech., Jun–Jul 2006