2017

TBA
Topology Seminar, University of Rochester, Rochester, NY, November 8, 2017
[announcement]

TBA
Topology Seminar, University of California, Berkeley, Berkeley, CA, October 11, 2017

TBA
Geometry and Topology Seminar, San Francisco State University, San Francisco, CA, October 6, 2017
[announcement]

Resonance varieties for matroids
Thematic week Matroids in Boston, Northeastern University, Boston, MA, September 13, 2017

Polyhedral products, duality properties, and CohenMacaulay complexes
Special Session on Geometry and Combinatorics of Cell Complexes, Mathematical Congress of the Americas,
Montréal, Canada, July 28, 2017. [abstract] [slides]

Arrangement complements and Milnor fibrations
Special Session on Advances in Arrangement Theory, Mathematical Congress of the Americas,
Montréal, Canada, July 25, 2017. [abstract] [slides]

Formality notions for spaces and groups
Workshop on Nilpotent Fundamental Groups, Banff International Research Station, Alberta, Canada, June 22, 2017.
[slides] [video]

Duality and resonance
Colloquium, University of Bremen, Germany, June 13, 2017
[announcement]

Resonance varieties
Summer School and Workshop ET'nA 2017: Encounter in Topology and Algebra,
Scuola Superiore di Catania, Italy, May 31, 2017. [slides]

Algebraic invariants of pure braidlike groups
Workshop on Braids in Algebra, Geometry, and Topology,
International Centre for Mathematical Sciences, Edinburgh, UK, May 23, 2017.
[slides]

Representation varieties and polyhedral products
Special Session on Representation Spaces and Toric Topology,
AMS Spring Eastern Sectional Meeting, Hunter College, CUNY, New York, NY, May 6, 2017 [slides]

Representation varieties and cohomology jump loci
Singularities in the Midwest, IV,
University of Wisconsin, March 17, 2017. [slides]
2016

On the topology of line arrangements
Summer Conference on Hyperplane Arrangements, at Hokkaido University, Sapporo, Japan, August 812, 2016. [slides]

The pure braid groups and their relatives
Topology Seminar, Mathematics Institute of the Romanian Academy, Bucharest, Romania, June 17, 2016. [slides]

An introduction to resonance varieties (2 lectures)
Doctoral School and Workshop on Topology and Geometry of Arrangements,
University of Fribourg, Switzerland, June 8, 2016.

Fundamental groups in algebraic geometry and threedimensional topology
Colloquium, University of Fribourg, Switzerland, June 7, 2016.
[announcement] [poster] [slides]

Residual finiteness properties of fundamental groups
Number Theory and Algebraic Geometry Seminar,
KU Leuven, Belgium, May 18, 2016. [abstract] [slides]

Fundamental groups in complex geometry and 3dimensional topology
Topology Seminar, Brandeis University, March 29, 2016.
[abstract] [slides]

Algebraic models for Sasakian manifolds and weightedhomogeneous surface singularities
Workshop on Singularities and Topology, at Université de Nice, France, March 79, 2016. [abstract] [slides]

The pure braid groups and their relatives
Algebra and Geometry Seminar,
University of Caen, France, January 5, 2016. [slides]
2015

Complex geometry and 3dimensional topology
Workshop on Geometric Group Theory and Geometric Topology,
at the University of Virginia, Charlottesville, VA, October 17, 2015.
[slides]

Group actions on manifolds and formality properties
30th British Topology Meeting,
at Queen's University Belfast, Belfast, Northern Ireland, UK, September 8, 2015.

Sigmainvariants and tropical varieties
Conference on Finiteness Conditions in Topology and Algebra,
at Queen's University Belfast, Belfast, Northern Ireland, UK, September 1, 2015.

Hyperplane arrangements: at the crossroads of topology and combinatorics
PIMS Distinguished Lecture, University of Regina, Saskatchewan, Canada, August 14, 2015.
[announcement] [slides]

Hyperplane arrangements: Cohomology jump loci and Milnor fibrations
Workshop on Computational Geometric Topology in Arrangement Theory,
at ICERM, Brown University, Providence, RI, July 610, 2015.
Talk 1: [slides]
[video].
Talk 2:
[slides]
[video].

Topology of complex arrangements
The Eighth Congress of Romanian Mathematicians,
Iasi, Romania, June 30, 2015 [slides]

Deconstructing formality
Topology Seminar, Mathematics Institute of the Romanian Academy, Bucharest, Romania, June 19, 2015 [abstract]

Hyperplane arrangements and Milnor fibrations
Geometry & Topology Seminar,
University of Western Ontario, London, ON, Canada, June 1, 2015 [slides]

Resonance, representations, and the Johnson filtration
Geometry/Topology Seminar,
University of Chicago, May 8, 2015 [slides]

Geometry and topology of cohomology jump loci (8 lectures)
Geometric Literacy course,
University of Chicago, April 20May 8, 2015.

Algebraic models and the Tangent Cone theorem
Representation Theory and Related Topics Seminar,
Northeastern University, April 10, 2015 [abstract] [slides]

Fundamental groups in topology and geometry
Math Club Lecture Series,
Northeastern University, March 26, 2015

Algebraic models and cohomology jump loci
Intensive research period on Algebraic Topology, Geometric and Combinatorial Group Theory,
at the Centro di Ricerca Matematica Ennio De Giorgi,
Pisa, Italy, February 24, 2015 [announcement] [slides]
2014

Topology of line arrangements
Conference on Configuration Spaces–Geometry, Topology and Representation Theory,
Palazzone di Cortona,
Italy, September 1, 2014
[slides]

Combinatorial covers, abelian duality, and propagation of resonance
Conference on Topology of Torus Actions and Applications to Geometry and Combinatorics,
Korea Advanced Institute of Science and Technology,
Daejeon, Korea, August 7, 2014
[video]
[slides]

Complex geometry and threedimensional topology
Algebra and Geometry Seminar,
University of Caen, France, June 17, 2014. [slides]

Hyperplane arrangements, Milnor fibrations, and boundary manifolds
Algebra, Geometry and Topology Seminar, Université de Nice, France, June 10, 2014. [slides]

Combinatorial covers, abelian duality, and propagation of resonance
Algebra, Topology and Combinatorics Seminar, Università di Pisa, Italy, May 29, 2014. [abstract] [slides]

Topology of hyperplane arrangements
Baby Geometry Seminar, Università di Pisa, Italy, May 28, 2014. [abstract] [slides]

Milnor fibrations of hyperplane arrangements
Focused Research Group on Hyperplane Arrangements, Wonderful Compactifications, and Tropicalization,
Banff International Research Station, Alberta, Canada, April 20, 2014.
[slides]

Homological finiteness in the Johnson filtration
Geometry & Topology Seminar, Yale University, February 4, 2014. [slides]

Abelian duality and propagation of resonance
Special Session on
Hyperplane Arrangements and Applications,
Joint Mathematics Meetings,
Baltimore, MD, January 14, 2014
[abstract]
[slides]
2013

Milnor fibrations of hyperplane arrangements
Geometry Colloquium,
Hokkaido University,
Sapporo, Japan, November 22, 2013. [abstract]
[slides]

Topology and combinatorics of Milnor fibrations of hyperplane arrangements
Conference on Hyperplane Arrangements
and Characteristic Classes, Research Institute for Mathematical Sciences,
Kyoto, Japan, November 13, 2013 [slides]

Complex geometry and lowdimensional topology
Geometry and Topology Seminar, Max Planck Institute for Mathematics,
Bonn, Germany, October 28, 2013. [abstract]
[slides]

Hyperplane arrangements: at the crossroads of topology and combinatorics
Colloquium, Goethe University Frankfurt, Germany,
October 25, 2013
[abstract]
[slides]

Milnor fibrations of hyperplane arrangements
Colloquium, University of Bremen, Germany, October 22, 2013
[announcement]
[slides]

Topology and geometry of cohomology jump loci
Conference on Experimental
and Theoretical Methods in Algebra, Geometry and Topology, Eforie Nord, Romania, June 24, 2013
[slides]

Milnor fibrations of hyperplane arrangements
Algebraic Geometry and Topology Seminars,
Mathematics Institute of the Romanian Academy,
Bucharest, Romania, June 14, 2013
[announcement]
[slides]

Automorphism groups, Lie algebras, and resonance varieties
Colloquium, University of Western Ontario, London, ON, Canada, April 25, 2013
[abstract] [slides]

Multinets, parallel connections, and Milnor fibrations of arrangements
Special Session on
Singular Spaces in Geometry, Topology, and Algebra,
AMS Spring Western Sectional
Meeting, Boulder, CO, April 14, 2013
[abstract]
[slides]
2012

Complex geometry and 3dimensional topology
GTA MiniWorkshop on
Geometry and Topology,
University of Sydney, December 10, 2012
[abstract]
[slides]

The rational homology of smooth real toric varieties
Geometry Topology and Analysis Seminar,
University of Sydney, November 26, 2012
[abstract]
[slides]

The rational homology of real toric manifolds
MiniWorkshop on Cohomology Rings and Fundamental Groups of Hyperplane Arrangements, Wonderful Compactifications, and Real Toric Varieties,
Mathematisches Forshungsinstitut, Oberwolfach, Germany, October 5, 2012
[extended abstract]

Resonance varieties
MiniWorkshop on Cohomology Rings and Fundamental Groups of Hyperplane Arrangements, Wonderful Compactifications, and Real Toric Varieties,
Mathematisches Forshungsinstitut, Oberwolfach, Germany, October 2, 2012
[extended abstract]

Resonance and representations
GASC Seminar, Northeastern University, September 17, 2012
[abstract]

Momentangle complexes, toric manifolds, and twisted cohomology
Topology Seminar, Mathematics Institute of the Romanian Academy, Bucharest, Romania, June 22, 2012
[slides]

Topology of Milnor fibrations of hyperplane arrangements (3 lectures)
School and Workshop on
Hyperplane Arrangements and Related Topics, University of Pau, Pau, France, June 1115, 2012

GreenLazarsfeld sets and the topology of smooth algebraic varieties
Workshop on Singularities of Differential Equations in Algebraic Geometry,
Centre International de Rencontres Mathématiques,
Luminy, France, June 8, 2012
[slides]

The rational cohomology of smooth, real toric varieties
Workshop on Arrangements and Configuration Spaces,
University of Bremen, Bremen, Germany, May 25, 2012
[slides]

Fundamental groups and cohomology jumping loci
Geometric Topology Seminar, Max Planck Institute for Mathematics,
Bonn, Germany, May 7, 2012 [abstract]

Polyhedral products, quasitoric manifolds, and twisted cohomology
PrincetonRider workshop on Homotopy Theory and Toric Spaces,
Princeton University, February 23, 2012
[abstract]
[slides]

Sigma invariants of hyperplane arrangements
ColbyBatesBowdoin Collaborative Conference on Geometry, Topology, and Group Theory,
Bates College, Lewiston, ME, January 10, 2012

Geometric and homological finiteness in free abelian covers
Special Session on Geometric Invariants of Groups and Related Topics,
Joint Mathematics Meetings,
Boston, MA, January 7, 2012
[abstract]
[slides]
2011

The rational cohomology of real quasitoric manifolds
Conference on Toric Methods in Homotopy Theory,
Queen's University Belfast, Northern Ireland, UK, July 20, 2011
[slides]

Homological finiteness in the AndreadakisJohnson filtration
Algebra and Geometry Seminar, University of Caen, June 21, 2011. [slides]

The algebra and topology of partial products of circles
Groups and Braids Seminar,
University of Caen, June 8, 2011
[slides]

Abelian Galois covers and rank one local systems
Topology of Algebraic Varieties,
Université de Nice, France, May 25, 2011
[slides]

Betti numbers of abelian covers
Geometry and
Topology Seminar
, University of Wisconsin, May 6, 2011
[abstract]
[slides]

On the Johnson filtration of the automorphism group of a free group
Mathematics Seminar Series, U. Mass Boston, March 30, 2011 [abstract] [slides]

Betti numbers of abelian covers
Alumni Conference,
Northeastern University, March 12, 2011
2010

DwyerFried invariants
The Worldwide Center of Mathematics,
Cambridge, MA, July 9, 2010 [poster] [video]

Free abelian covers and arrangements of Schubert varieties
Workshop on combinatorial and geometric aspects of Hyperplane Arrangements,
Centro di Ricerca Matematica Ennio De Giorgi, Pisa, Italy, May 25, 2010
[abstract]
[slides]

Cohomology jumping loci and homological finiteness properties
Intensive research period on Configuration Spaces: Geometry, Combinatorics and Topology,
Centro di Ricerca Matematica Ennio De Giorgi, Pisa, Italy, May 1014, 2010
[lecture 1]
[lecture 2]
[lecture 3]

Topological methods in geometry, algebra, singularities, and combinatorics
Alumni Conference,
Northeastern University, March 20, 2010

Homological finiteness and the incidence correspondence
GASC Seminar,
Northeastern University, February 22, 2010 [abstract]
2009

Geometry and topology of cohomology jumping loci
Colloquium, University at Albany, December 4, 2009 [abstract] [slides]

How to compute the homology of the Milnor fibre of a nonisolated weighted homogeneous singularity
Singularities Seminar, University of Warwick, United Kingdom, November 23, 2009

Cohomology jump loci, Sigmainvariants, and fundamental groups of algebraic varieties
Topology Seminar, University of Oxford, United Kingdom, November 16, 2009
[announcement] [slides]

The Alexander polynomial and its friends
Geometry and Topology Seminar, University of Warwick, United Kingdom, November 5, 2009 [abstract]

Fundamental groups of smooth, (quasi) projective varieties
Singularity Day, University of Warwick, United Kingdom, November 4, 2009

Algebra and topology of rightangled Artin groups
Algebra Seminar, University of Leeds,
United Kingdom, October 19, 2009 [slides]

Partial products of circles
Algebra and Geometry Seminar,
VU University Amsterdam, The Netherlands, October 13, 2009 [slides]

Fundamental groups and cohomology support loci
Colloquium, University of Liverpool, United Kingdom, October 2, 2009 [slides]

On the geometry and topology of cohomology jump loci
MSJ Seasonal Institute on Arrangements of Hyperplanes, Hokkaido University, Sapporo, Japan, August 9, 2009
[slides]

Characteristic varieties and homological finiteness properties
LIB60BER  Topology of Algebraic Varieties, Jaca, Spain, June 24, 2009
[abstract]
[slides]

Jump loci and homological finiteness properties
Workshop on Fundamental Groups in Algebraic Geometry,
Université de Nice, France, May 26, 2009

Introduction to toric topology (with Alvise Trevisan)
Tapas Seminar, Northeastern University, May 14, 2009

A look at polyhedral products
Special Session on Topological Robotics, AMS Spring Eastern Section Meeting, Worcester, MA, April 24, 2009 [abstract]
2008

Geometry and topology of cohomology jumping loci
Topology Seminar, CUNY Graduate Center, November 20, 2008

Finiteness properties of groups and homology jumping loci
GASC Seminar, Northeastern University, October 27, 2008
[abstract]

BieriNeumannStrebelRenz invariants and homology jumping loci
Special Session on LowDimensional Topology, AMS Fall Eastern Section Meeting, Middletown, CT, October 12, 2008 [abstract]

Cohomology jumping loci
Topology Seminar, MIT, October 6, 2008

Spectral sequences and homology with local coefficients
Conference in honour of Peter Orlik, Fields Institute,
Toronto, ON, August 19, 2008 [abstract
] [audio]

Which Kähler groups are 3manifold groups?
International Conference in Algebraic Geometry,
Mathematics Institute of the Romanian Academy,
Bucharest, Romania, July 3, 2008 [abstract]
[slides]

Polyhedral products
Tapas Seminar,
Northeastern University, June 19, 2008
[abstract] [slides]

Topology and combinatorics of polyhedral products
Algebra and Geometry Seminar, Stockholm University,
Sweden, June 5, 2008 [announcement] [slides]

Minimal models in algebra, combinatorics and topology
Report on the Ph.D. Thesis of
Alexander Berglund, Stockholm University, Sweden, June 3, 2008 [announcement]

Homotopytype invariants of polyhedral products
Algebraic Topology Seminar,
Université Catholique de Louvain, Louvain la Neuve, Belgium, May 27, 2008

Which 3manifold groups are Kähler groups?
Special Session on Arrangements and Related Topics,
AMS Spring Southeastern Meeting, Baton Rouge, LA, March 29, 2008 [abstract] [slides]
2007

Which Kaehler groups are 3manifold groups?
Analysis and Geometry Seminar,
Northeastern University, November 30, 2007 [abstract]

Cohomology jumping loci and quasiprojective varieties
Topology Seminar,
Mathematics Institute of the Romanian Academy, Bucharest, Romania, October 12, 2007 [announcement]

The topology of the boundary manifold of a projective hypersurface
DModules and Singularities Seminar, Université de Nice, France, September 27, 2007

Generalized moment angle complexes
Algebra and Topology Seminar, Université de Nice, France, September 24, 2007

The equivariant spectral sequence and cohomology with local coefficients
MiniWorkshop on Topology of Closed OneForms and Cohomology Jumping Loci,
Mathematisches Forshungsinstitut, Oberwolfach, Germany, August 16, 2007
[extended abstract]

Jumping loci and finiteness properties of groups
MiniWorkshop on Topology of Closed OneForms and Cohomology Jumping Loci,
Mathematisches Forshungsinstitut, Oberwolfach, Germany, August 13, 2007
[extended abstract]

Fundamental groups and geometry
Tapas Seminar,
Northeastern University, June 6, 2007

Quasiprojective BestvinaBrady groups
Conference on Braids and their Ramifications,
Palazzone di Cortona, Italy, May 23, 2007
[abstract]
[slides]

Cohomology support loci, formality, and fundamental groups of quasiprojective varieties
Colloquium, Purdue University, West Lafayette, IN, March 7, 2007 [abstract]

Cohomology jumping loci
Alumni Conference, Northeastern University, February 24, 2007
2006

Some combinatorial constructions in topology and group theory
Topology Seminar, Università di Pisa, Italy, November 9, 2006
[announcement]

Boundary manifolds of complex hypersurfaces
Math Seminar, ICTP,
Trieste, Italy, November 6, 2006 [announcement]

Fundamental group computations in the theory of arrangements and related spaces
Workshop on Topological Methods in Combinatorics, Computational Geometry, and the Study of Algorithms
, MSRI, Berkeley, CA, October 2, 2006 [video]

Cohomology jumping loci and fundamental groups of projective varieties
Topology Seminar,
University of Oregon, Eugene, OR, September 25, 2006 [abstract]

Cohomology jumping loci, formality, and quasiprojectivity
Workshop on Recent Developments in Arrangements and Configuration Spaces,
MSRI, Berkeley, CA, August 8, 2006
[video]
2005

Configuration spaces and nonformality
Algebra Seminar,
University of Western Ontario, London, ON, Canada, November 21, 2005 [announcement
]

Boundary manifolds of complex projective hypersurfaces
GASC Seminar,
Northeastern University, November 7, 2005 [abstract]

On the algebra and topology of rightangled Artin groups
Algebraic Topology Seminar,
Université Catholique de Louvain, Louvain la Neuve, Belgium, October 24, 2005 [announcement
]

Algebraic invariants for BestvinaBrady groups
Hyperplane Arrangements Workshop,
Pacific Institute for the Mathematical Sciences, Vancouver, Canada, August 21, 2005

Free partially commutative groups and Lie algebras
Arrangements of Hyperplanes  Algebra, Combinatorics, Geometry, and Topology, Ascona, Switzerland, May 19, 2005
[abstract]

Configuration spaces and embedding obstructions (with David Wilson)
Tapas Seminar,
Northeastern University, May 11, 2005

BorsukUlam theorem and applications (with Marcus Fries)
Tapas Seminar, Northeastern University, May 9, 2005
[notes]

Graphs, groups, and polynomials (with Marcus Fries)
Research & Technology Expo 2005,
Northeastern University, March 16, 2005

Graphs, groups, and cohomology
GASC Seminar,
Northeastern University, February 14, 2005 [abstract]
2004

A look at rightangled Artin groups
Workshop on Combinatorial Aspects of Hyperplane Arrangements,
MSRI, Berkeley, CA, November 5, 2004 [video]

Topology of complex line arrangements
MSRIEvans talk,
University of California, Berkeley, CA, October 25, 2004 [abstract]

Lie algebras associated to arrangements
Introductory Workshop in Hyperplane Arrangements and Applications,
MSRI, Berkeley, CA, August 26, 2004
[video]

Fundamental groups and characteristic varieties
Introductory Workshop in Hyperplane Arrangements and Applications,
MSRI, Berkeley, CA, August 24, 2004
[video]

Topology of complex line arrangements (7 lectures)
MSRI Summer Graduate Program on Hyperplane Arrangements and Applications,
University of Oregon, Eugene, OR, August 213, 2004

Counting homomorphisms to finite groups
Tapas Seminar, Northeastern University, May 20, 2004
[notes]

What is a hyperplane arrangement?
Student Seminar, Northeastern University, February 10, 2004

On the decomposability of the holonomy Lie algebra of an arrangement
Special Session on Geometry and Combinatorics,
Joint Mathematics Meetings, Phoenix, AZ, January 8, 2004 [abstract]
2003

Arrangements of hyperplanes and graded Lie algebras
Topology Seminar,
University of Lille 1, Villeneuve d'Ascq, France, November 7, 2003 [abstract
]

Graded Lie algebras associated to hyperplane arrangements
GASC Seminar,
Northeastern University, October 20, 2003 [abstract]

Systolic inequalities and Massey products
Fifth Congress of Romanian Mathematicians, University of Pitesti, Romania, June 25, 2003

Free abelian covers and systolic inequalities
Analysis and Geometry Seminar,
Northeastern University, May 16, 2003 [abstract]

Alexander invariants and lower central series
Topology Seminar, Yale University, April 24, 2003

Fundamental groups of complex hyperplane arrangements
Special Session on Algebraic and Topological Combinatorics,
AMS Spring Eastern Section Meeting, New York, NY, April 12, 2003
[abstract]
2002

Counting finiteindex subgroups and subalgebras
Algebra Seminar,
University of Western Ontario, London, ON, Canada, December 6, 2002

Rational homotopy groups, lower central series, and Koszul algebras
Colloquium, University of Western Ontario, London, ON, Canada, December 5, 2002 [abstract]

Counting finiteindex subgroups via padic integration
Basic Notions Seminar,
Northeastern University, October 31, 2002

Zeta functions of groups
Basic Notions Seminar,
Northeastern University, October 17, 2002

Chen Lie algebras and combinatorics of arrangements
Special Session on Arrangements of Hyperplanes, AMS Fall Central Section Meeting, Madison, WI, October 13, 2002 [abstract]

Chen ranks of arrangements
Special Session on Algebraic Geometry and Combinatorics, AMS Spring Western Section Meeting, Portland, OR, June 21, 2002

Fundamental groups of complex hyperplanes arrangements
Topology Seminar,
The Ohio State University, Columbus, OH, May 24, 2002

Virtual jumping loci
MiniWorkshop on Cohomology Jumping Loci, Mathematisches Forshungsinstitut,
Oberwolfach, Germany, March 9, 2002

Torsion in the homology of the Milnor fiber of a multiarrangement
MiniWorkshop on Cohomology Jumping Loci,
Mathematisches Forshungsinstitut, Oberwolfach, Germany, March 6, 2002

Zeta functions of OrlikSolomon algebras
MiniWorkshop on Cohomology Jumping Loci,
Mathematisches Forshungsinstitut, Oberwolfach, Germany, March 5, 2002

Lower central series, free resolutions, and homotopy Lie algebras of arrangements
NSFCBMS Regional Research Conference Arrangements and Mathematical Physics, LSU, Baton Rouge, January 11, 2002
[abstract]
[slides]
2001

Fundamental groups of hyperplane arrangements
Colloquium, University of Rochester, Rochester, NY, November 9, 2001

Rescaling formulas for rational homotopy groups
Topology Seminar, University of Rochester, Rochester, NY, November 8, 2001

Lower central series and free resolutions of arrangements
Special Session on Algebraic and Topological Combinatorics, AMS Fall Eastern Section Meeting, Williamstown, MA, October 13, 2001 [abstract
] [slides]

Arrangements of hyperplanes and enumerative techniques in group theory (2 lectures)
Topology Seminar,
Mathematics Institute of the Romanian Academy, Bucharest, Romania, July 13 and 20, 2001

Platonic solids
GAANN Seminar, Advanced Scientific Computation Center, Northeastern University, May 1, 2001
2000

Topology of complex line arrangements
Colloquium, McMaster University, Hamilton, ON, Canada, December 15, 2000

Fundamental groups of arrangements
Workshop on Arrangements,
Forschungsinstitut für Mathematik, ETH Zürich, December 7, 2000
[abstract]

Topology of hyperplane arrangements (Invited address)
A.M.S. Fall Eastern Section Meeting, New York, NY, November 5, 2000
[slides]

The Poincaré conjecture
Basic Notions Seminar,
Northeastern University, October 26, 2000

Counting subgroups of finite index
Graduate Student Seminar, Northeastern University, May 15, 2000
[slides]

Homotopy groups and characteristic varieties
NU Tech Expo 2000, Northeastern University, May 11, 2000
[abstract]

Counting representations onto finite groups, and torsion points on characteristic varieties
Special Session on Enumerative Geometry in Physics, AMS Spring Eastern Section Meeting, Lowell, MA, April 2, 2000

Cohomological jumping loci and finiteindex subgroups
Geometric Analysis Seminar, Technion, Haifa, Israel, March 16, 2000

Hall invariants and characteristic varieties
Geometry and Topology Seminar, Tel Aviv University, Israel, March 14, 2000

Braids, links, and hyperplane arrangements
Colloquium, Bar Ilan University, Tel Aviv, Israel, March 8, 2000 [announcement]

Hall invariants and the Alexander stratification of character varieties
Geometric Topology Seminar, Columbia University, February 25, 2000 [announcement]
1999

Braids, links, and hyperplane arrangements
Colloquium, University of Iowa, December 8, 1999

Representations to finite groups and homology jumping loci
Topology Seminar, University of Iowa, December 7, 1999

Topology of hyperplane arrangements
Algebraic Geometry Seminar, University of Illinois at Chicago, December 6, 1999

Cohomology jumping loci and finite covers
Topology Seminar, Brandeis University, September 28, 1999

Recognizing surfaces
(with Ivo Nikolov)
Poster Session: Connections '99,
Northeastern University, May 10, 1999
[poster]

Cohomology rings, nilpotent quotients, and resonance varieties
GASC Seminar,
Northeastern University, April 12, 1999 [abstract]
1998

Combinatorics and topology of complements of planes in R^{4}
Workshop on Mathematics Related with Arrangements of Hyperplanes, Tokyo Metropolitan University, Tokyo, Japan, July 16, 1998

On the difference between the fundamental groups of real and complex arrangements
Meeting on Fundamental Groups in Geometry, Mathematisches Forshungsinstitut, Oberwolfach, Germany, May 6, 1998

Fundamental groups of real and complex arrangements (with Daniel Matei)
Centennial Poster Session, Northeastern University, May 4, 1998
[abstract]

Characteristic varieties of real and complex arrangements
Combinatorics Seminar,
MIT, March 18, 1998 [abstract]
1997

Homotopy types of subspace arrangements
Topology Seminar, Brandeis University, November 18, 1997

Topology and combinatorics of arrangements
Colloquium, Laboratoire de Topologie,
Université de Bourgogne, Dijon, France, July 2, 1997

Hyperplane arrangements: Alexander invariants, Chen groups, and characteristic varieties
Differential Geometry Seminar, Institut Élie Cartan,
Université Henri Poincaré, Nancy, France, July 1, 1997

Topology and combinatorics of hyperplane arrangements
Differential Geometry Seminar,
Institut Élie Cartan, Université Henri Poincaré, Nancy, France, June 24, 1997

Hyperplane arrangements and braid groups
TopologyGeometry Seminar, IRMA,
Université Louis Pasteur, Strasbourg, France, June 20, 1997

Topology and combinatorics of hyperplane arrangements
Geometry Seminar, Université de Haute Alsace,
Mulhouse, France, June 19, 1997

Framed manifolds, knots, and homology spheres
Differential Geometry Seminar,
Institut Élie Cartan, Université Henri Poincaré, Nancy, France, June 17, 1997

Alexander invariants of arrangements
Minisymposium on Arrangements of Hyperplanes,
Mathematics Ph.D. Centennial Conference, University of Wisconsin, May 20, 1997
[slides]

Braid monodromy of arrangements
Analysis Seminar, Indiana UniversityPurdue University at Indianapolis, January 24, 1997

Braid monodromy and Alexander invariants of arrangements
TopologyGeometry Reading Seminar, Indiana University, January 23, 1997

Hyperplane arrangements and braid groups
Topology Seminar, Indiana University, January 22, 1997
1996

Gromov norm and bounded cohomology (6 lectures)
Basic Notions Seminar,
Northeastern University, SeptemberNovember 1996

Combinatorics and topology of complex line arrangements
Combinatorics Seminar, Northeastern University,
September 9, 1996

Topology of hyperplane arrangements
(2 talks), Topology Seminar, Louisiana State University, April 2223, 1996

Hyperplane arrangements, braid monodromy, and representations of braid groups
Special Session on Low Dimensional Topology,
AMS Meeting, Baton Rouge, LA, April 20, 1996

Braid monodromy of hyperplane arrangements and representations of braid groups
Special Session and Workshop on Arrangements of Hyperplanes,
AMS Central Section Meeting, Iowa City, IA, March 23, 1996
1995

The braid monodromy of complex hyperplane arrangements
Topology and Geometry Seminar, SUNY at Stony Brook, November 14, 1995

The KnizhnikZamolodchikov equations (5 lectures)
Basic Notions Seminar,
Northeastern University, October 19November 29, 1995

The braid monodromy of complex hyperplane arrangements
GAS Seminar,
Northeastern University, October 10, 1995

The SeibergWitten equations (7 lectures)
Basic Notions Seminar,
Northeastern University, JanuaryMarch 1995
1994

Chen groups of arrangements
Colloque sur les Arrangements d'Hyperplans, Centre International de Rencontres Mathématiques, Luminy, France, July 7, 1994

The Chen groups of hyperplane arrangements
GAS Seminar,
Northeastern University, June 20, 1994

Complements of discriminants and braid arrangements
GAS Seminar,
Northeastern University, May 23, 1994

4Manifolds (3 lectures)
Basic Notions Seminar,
Northeastern University, February 17, 1994
1993

Alexander modules of hyperplane arrangements
Topology and Group Theory Conference, SUNY at Albany, October 31, 1993

Alexander modules of arrangements
GAS Seminar,
Northeastern University, September 27, 1993

Complements of hyperplane arrangements
Cech Centennial Homotopy Theory Conference, Northeastern University, June 25, 1993

Milnor fibrations of homogeneous polynomials
GAS Seminar,
Northeastern University, May 10, 1993

Introduction to quantum field theory and 3manifold invariants
AnalysisGeometry Seminar,
Northeastern University, February 19, 1993
1992
1991

Homology isomorphisms between algebraic groups made discrete
Topology and Group Theory Conference, SUNY at Albany,
October 13, 1991

Homology of Lie groups made discrete
GAS Seminar,
Northeastern University, October 4, 1991

Framespinning and nonreflexive knots
Colloquium, SUNY at Binghamton, May 13, 1991

Knots and framed manifolds
GAS Seminar,
Northeastern University, May 10, 1991

Highdimensional knots with the same complement
Topology Seminar, MIT,
February 11, 1991
1990

Framed manifolds and highdimensional knots with the same complement
Colloquium, SUNY at Albany, November 11, 1990

Inequivalent framespun knots with the same complement
Topology Seminar, Yale University, May 11, 1990

Framespinning and nonreflexive knots
Topology Seminar, Brandeis University, April 20, 1990
1989

The second homology of groups of germs of diffeomorphisms
Special Session, A.M.S. Meeting, Hoboken, NJ, October 22, 1989

The second homology of jet groups
Geometry Seminar, Northeastern University, October 1989

Homology spheres, framed bordism, and the plus construction
Topology Seminar,
Northeastern University, October 2, 1989
1988

Iterated spinning and homology spheres
Topology Seminar, Yale University, 1988
1987
1986

The homotopy type of fourdimensional manifolds
Ontario Topology Conference, McMaster University, Hamilton, ON, Canada, October 1986

Homotopytype invariants of 4manifolds
Fall Foliage Topology Conference, Dartmouth College, September 27, 1986

Homotopytype invariants of fourdimensional manifolds
Geometry Seminar, Northeastern University, April 1986
1985

Homology 4spheres
Topology Seminar, Yale University, October 17, 1985

Rational homotopy theory of Kähler manifolds (4 lectures)
Rational Homotopy Seminar, Yale University, 1985

Knots with finite commutator subgroup
Topology Seminar, Yale University, 1985

Immersed spheres in rational surfaces
Topology Seminar, Yale University, 1985
1984

Homotopytype invariants of 4dimensional knot complements
Topology Seminar, Yale University, 1984

The homotopy type of 4dimensional knot complements
Topology Seminar, Columbia University, 1984

Euler characteristics of groups (3 lectures)
Group Theory Seminar, Columbia University, 1984
1983