Simpson: Recent and Upcoming Talks
I am Stephen G. Simpson, a mathematician at
Penn State University.

A writeup of my invited talk at the Feferman Symposium (Stanford,
December 1998) is available.

A writeup of my invited talk at the CTA
Conference (Boulder, June 1999) is available.

Transparencies for my invited presentations at the New York City Logic Conference
(November 1999) are available.

Transparencies for my invited talk at the CMU Philosophy of Mathematics Workshop
(December 2000) are available.

Transparencies and other materials for my invited talk at the Workshop on
Berechenbarkeitstheorie (Oberwolfach, January 2001) are
available.

I organized a Special Session on Reverse Mathematics and gave an
invited talk at the 2001 Annual
Meeting of the Association for
Symbolic Logic in Philadelphia, March 1113, 2001. My transparencies are available.

I gave an invited onehour talk in a Symposium on Hilbert's Problems
Today in Pisa, Italy, April 57, 2001. My abstract and transparencies are available.

I gave an invited onehour talk at a MAMLS meeting in Washington DC,
April 2122, 2001. My transparencies are available.

I gave an invited onehour talk at the
University of Minnesota, May 2, 2001.
My abstract and transparencies are
available.

I gave an invited onehour talk as
part of
a Symposium
on Reverse Mathematics and Computability Theory, at a meeting of
the American Philosophical
Association, in Minneapolis, May 35, 2001.
My abstract and transparencies are
available.

I gave an invited talk at CMAF
at the University of Lisbon, Portugal, July 19, 2001. My abstract and transparencies are
available.

I gave an invited 45minute talk
as part of a Special Session on Proof Theory and Foundations of
Mathematics, at a sectional meeting of the American Mathematical Society, in
Columbus, Ohio, September 2123, 2001. My abstract and transparencies are
available.

I gave an invited 60minute plenary
talk at the 2002 Annual
Meeting of the Association for
Symbolic Logic, in Las Vegas, Nevada, June 14, 2002. My abstract and transparencies are
available.

I gave an invited 25minute talk
at a special session on Computability
and Models, at the American
Mathematical Society Annual Meeting in Baltimore, January 1518,
2003. My abstract and
transparencies are available.

On February 19, 2003, I gave an invited 1hour talk
in the Mathematical
Logic Seminar at Carnegie Mellon
University.

On February 20, 2003, I gave a talk
in the Pure
and Applied Logic Colloquium at Carnegie Mellon University.

On June 2327, 2003, I gave a series
of 5 lectures at the Summer School
and Workshop on Proof Theory, Computation and Complexity, at the
Technical University of
Dresden, Germany. My lecture
notes are available.

On August 26, 2003 I gave an invited
talk in the Mathematical
Logic Seminar at Carnegie Mellon
University.

On March 6, 2004 I gave an invited
onehour talk at a MAMLS
meeting, held at Hofstra University, in Hempstead, Long Island,
NY. My abstract and
transparencies are available.

In October 24, 2004 I gave an invited 20minute talk in a special
session on Computability
Theory and Applications, part of a sectional
meeting of the American Mathematical
Society, at Northwestern University, Evanston, Illinois. My abstract and transparencies are
available.

In January 2005 I gave an invited 45minute talk in
a special
session on Reverse Mathematics, part of
the AMSASLMAA
Joint Mathematics Meetings, January 58, 2005, in Atlanta,
Georgia. My abstract and
transparencies are available.

On August 4 and August 8, 2005, I gave two invited 1hour talks at a
workshop
on Recursion
Theory, part of a program
on Computational
Prospects of Infinity at
the Institute for Mathematical
Sciences of the National
University of Singapore.
My abstracts and transparencies
are available. A paper based on one
of my talks is available.

On October 6, 2005 I gave an invited
talk in the Mathematical
Logic Seminar at Carnegie Mellon
University. My abstract and
transparencies are available. (This talk was originally scheduled
for September 1, 2005.)

During August 711, 2006 I attended and gave
an invited talk at
a workshop
on algorithmic randomness at
the American Institute of
Mathematics in Palo Alto, California.
My transparencies are available.

During August 28  September 1, 2006 I gave a series of invited talks
while visiting the Department of
Mathematics of the University of
Notre Dame in South Bend, Indiana. In particular, I gave a Logic
Seminar talk entitled Mass Problems and Degrees of
Unsolvability.
My transparencies are available.

During October 2829, 2006 I gave an invited talk at a regional
meeting of the American Mathematical
Society in Storrs, Connecticut, as part of a special session, Computability
Theory, in honor of Manuel Lerman's retirement. I spoke on
Mass Problems and Hyperarithmeticity. My abstract is available.

During November 15, 2006 I attended and gave a twohour invited tutorial at the Third International Conference on
Computability and Complexity in Analysis, at the Department of Mathematics of the University of Florida. This conference
was part of a special logic year
at the University of Florida, September 2006  June 2007, sponsored by
the National Science Foundation.

During November 1417, 2006 I visited the Department of Mathematics at the University of Florida. I gave a
talk in the Logic
Colloquium. My abstract and
transparencies are available.

On January 21, 2007 I gave an invited 50minute talk at the Massachusetts Institute of Technology as
part of a small conference, Topics in
Computability, in honor of Richard Shore's 60th birthday. My
abstract and transparencies are
available.

I gave an invited talk as part of
a special session on Computability Theory at the 2007 Annual
Meeting of the Association for
Symbolic Logic, in Gainesville, Florida, March 1013, 2007. My abstract and transparencies are
available.

From May 27 to June 10, 2007, I participated in a special
program on Proof Theory at the Max Planck Institute for
Mathematics in Bonn, Germany. My abstracts and slides are
available.

On Friday September 14, 2007 I visited the Department of Mathematics
at the University of Chicago. I gave a seminar talk on mass problems.
My abstract and slides are
available.

During September 1519, 2007 I participated in a workshop on
algorithmic randomness at the University of Chicago. This is part
of our large
collabortive research project which is funded
by the National Science Foundation. As part of the workshop I
gave a 2hour tutorial and a 1hour research talk. My abstract and slides are available.

During Fall 2007 I gave a series of talks in the Penn State Logic Seminar. The
theme of the talks is mass problems. My abstracts and slides are available.

During October 1821, 2007 I participated in a Dynamical Systems Workshop here at the
Pennsylvania State University. I gave a onehour talk on degrees of
unsolvability of 2dimensional subshifts of finite type. My abstract and slides are available.

During February 2023, 2008 I visited the Mathematical
Institute of Tohoku University, in Sendai, Japan. I spoke on mass
problems at a workshop in Sendai and a spring school in Matsushima.
My abstracts and slides are
available.

During April 612, 2008 I was an invited participant in a conference
on Proof Theory and Constructive Mathematics, held at the Mathematical Research Institute in
Oberwolfach, Germany. My research
report and slides are available.

During May 1923, 2008 I participated as an invited plenary speaker in
a conference on
Computability, Complexity and Randomness held at Nanjing
University, Nanjing, China. My abstract and slides are available.

During July 38, 2008 I participated as an invited plenary speaker at
Logic Colloquium 2008, the
annual summer meeting of the Association for Symbolic Logic, held in
Bern, Switzerland. My abstract and
slides are available.

On November 13, 2008 I gave a talk in the Dynamical
Systems Seminar in the Department of Mathematics at the University
of Maryland. My abstract and
slides are available.

During December 712, 2008 I participated as an invited plenary
speaker at a conference on Computability,
Reverse Mathematics and Combinatorics at the Banff International Research Station for
Mathematical Innovation and Discovery in Banff, Canada. My abstract and slides are
available.

During January 56, 2009 I participated as organizer and speaker in a
Special
Session on Logic and Dynamical Systems, sponsored by the American Mathematical Society and the
Association for Symbolic Logic.
The session was part of the Joint Mathematics
Meetings in Washington, DC. Some additional information about the
session is available. My abstract and slides are available.
 During January 30  February 1, 2009 I participated as an
invited plenary speaker at the 15th Very
Informal Gathering of Logicians at UCLA. This VIG was in
honor of the 60th birthday of my former Ph.D. student John Steel. My abstract and slides are available.
 During April 35, 2009 I participated as an invited speaker at a
philosophy
of mathematics conference at New York University. My slides and the text of my talk
are available.

During May 2731, 2009 I participated in a workshop on algorithmic
randomness at the University of Wisconsin. This is part of our large collabortive research
project which is funded
by the National Science Foundation. As part of the workshop I
gave a 1hour talk. My abstract and
slides are available.
 During June 2229, 2009 I participated as an invited plenary
speaker at the 11th Asian
Logic Conference in Singapore. My abstract and slides are available.
 On September 14, 2009 I gave a talk in the Computer Science
Theory Seminar in the Department
of Computer Science and Engineering here at Penn State. My slides are available.
 During November 68, 2009 I participated as an organizer and
invited speaker in a workshop on Reverse
Mathematics: Foundations and Applications at the University of
Chicago. My slides are
available.

During January 48, 2010 I participated in a workshop
on algorithmic randomness at the University of Hawaii. This is
part of our large
collabortive research project which is funded
by the National Science Foundation. As part of the workshop I
gave a 1hour talk. My abstract and
slides are available.

During February 812, 2010 I participated in a conference on Dynamics
and Computation at the Centre International de Rencontres
Mathematiques (CIRM) near Marseille, France. As part of the
conference I led a 90minute session on degrees of unsolvability and
symbolic dynamics. My slides
are available.
 During March 2728, 2010 I gave an invited talk as part of a
special
session on Interactions between Logic, Topology, and Complex
Analysis, at a regional meeting of the American Mathematical
Society in Lexington, Kentucky.
My abstract and slides are
available.
 During May 2428, 2010 I was planning to give an invited plenary
talk at the
5th
Conference on Logic, Computability and Randomness, held at Notre
Dame University. My slides are
available. Unfortunately, due to illness, I was unable to participate
in the conference. However, Alexander Shen gave my talk for me.
 During November 57, 2010 I attended
an AMS
sectional meeting at Notre Dame University. There I gave an
invited talk in a
Special
Session on Computability and Applications.
My abstract and slides are
available.
 During January 31  February 4, 2011 I was planning to give an
invited plenary talk at
the Eighth International
Conference on Computability and Complexity in Analysis (CCA 2011)
in Cape Town, South Africa.
My abstract and slides are
available. Unfortunately, due to illness, I was unable to attend the
conference.
 During July 2529, 2011 I attended and gave an invited plenary
talk at a
Workshop
on Infinity and Truth at the National University of Singapore.
My abstract and slides are
available.
 During September 1618, 2011 I attended and gave an invited
plenary talk at
a Reverse
Mathematics Workshop at the University of Chicago.
My abstract and slides are
available.
 During February 2023, 2012 I attended and gave an invited plenary
talk at a
Workshop
on Proof Theory and Computability in Tokyo, Japan. More
information about the workshop is
here.
My abstract and slides are
available.
 On March 7, 2012 I gave an invited seminar talk in the Department
of Mathematics at the University of California in San Diego. My
talk was based on the one that I had previously given in Tokyo in
February 2012.
 During July 26, 2012 I attended and gave an invited plenary talk
at CCR 2012,
the
Seventh International Conference on Computability, Complexity and
Randomness, at the Isaac
Newton Institute for Mathematical Sciences in Cambridge,
England. My abstract and
slides are available.
 During February 1820, 2013 I was an invited participant and gave
an invited plenary talk in
a workshop on
Computability Theory and Foundations of Mathematics (CTFM 2013)
at the Tokyo Institute of Technology.
My abstract and slides are
available.
 During February 2223, 2013 I was an invited participant and gave
a twohour tutorial at
the Sendai Logic
School at Tohoku University in Sendai, Japan.
My abstract and slides are
available.
 During April 2728, 2013 I and my Ph.D. students Phil Hudelson and
Noopur Pathak attended and gave invited presentations in a
Special
Session on Computability and Complexity in Discrete and Continuous
Worlds. This was part of a meeting of the American Mathematical
Society at Iowa State University.
Our abstracts and slides are
available.
 During November 2526, 2013 I was an invited participant in a
Royal Society International Scientific
Seminar, Computational
Interpretations of Mathematical Theorems, held at the Kavli
Royal Society Centre, Chicheley Hall, Milton Keynes,
Buckinghamshire, UK. My abstract and
slides are available.
 During January 2730, 2014 I visited the Cornell University
Department of Mathematics and gave an invited talk.
My abstract and slides are
available.
 During February 1720, 2014 I participated as an invited
speaker
at Computability
Theory and Foundations of Mathematics (CTFM 2014) at the Tokyo
Institute of Technology.
My abstract and slides are
available.
 On February 21, 2014 I gave a 1hour tutorial at
the Sendai
Logic School at the Tokyo Institute of Technology.
My abstract and slides are
available.
 During June 913, 2014 I gave an invited talk
at CCR
2014. This was part of a monthlong
Algorithmic
Randomness event held June 230, 2014 at the National University
of Singapore. My abstract and
slides are available.
 During September 29  October 2, 2014 I was an invited speaker at
a conference on Proof
Theory, Modal Logic and Reflection Principles in Mexico City.
My abstract and slides are
available.
 On October 29, 2014 I gave (via Skype) an invited talk in the
Online Logic Seminar at Moscow State University.
My abstract and slides are
available.
 During March 2528, 2015 I gave an invited talk at a recursion
theory special session of
the 2015 Annual North
American Meeting of the Association for Symbolic Logic, held at
the University of Illinois in UrbanaChampaign.
My abstract and slides are
available.
 During April 14, 2015 I served as an invited Scholar of
Consequence with the University of
Connecticut Group in Philosophical and Mathematical Logic. As
part of this visit I delivered
their Annual
Logic Lecture. My abstract,
references, and slides for the lecture are available.
 During June 2728, 2015 I gave an invited 1hour talk at
a Workshop on
Computability Theory, held in Bucharest, Romania.
My abstract and slides are
available.
 During June 29  July 3, 2015 I gave an invited 3hour tutorial
at Computability in Europe
(CiE 2015), held in Bucharest, Romania. A
writeup of my tutorial is
available. My slides are also
available.
 During October 1922, 2015 I visited Cornell University and gave
an invited 1hour talk in the Logic Seminar there.
My abstract and slides are
available.
 During January 39, 2016 I gave an invited 1hour talk at the
conference New
Challenges in Reverse Mathematics, held at
the Institute for Mathematical
Sciences, National University of Singapore.
My slides are available.
 On January 6, 2016 I delivered a Public Lecture at
the National University of
Singapore. Some additional
information is available.
 During February 67, 2016 I gave an invited talk at a
Workshop on Ordered
Algebraic Structures and Logic, held at the Department of
Mathematics at Vanderbilt University.
My abstract and slides are available.
 During September 2023, 2016 I gave an invited 2hour
tutorial
at Computability
Theory and Foundations of Mathematics (CTFM 2016), held at
Waseda University and the Tokyo Institute of Technology.
My abstract and slides are
available.
 On November 2, 2016 I gave a talk in the
Group
Theory and Topology Seminar at Vanderbilt University.
My abstract and slides are
available.
 During December 49, 2016 I was scheduled to participate in the workshop
Algorithmic
Randomness Interacts with Analysis and Ergodic Theory, held at
the Banff International Research
Station, Casa Matemática Oaxaca, in Oaxaca, Mexico.
Unfortunately, I had to cancel my participation due to illness.
 On February 22, 2017 I gave a talk in the
Group
Theory and Topology Seminar at Vanderbilt University. My
abstract
is available.
 During April 2628, 2017 I
visited Louisiana State University
and gave a talk in
the Philosophy Department. Further information
is available.
 During June 1520, 2017 I visited the University of Paris 7
Diderot and gave a talk in an ongoing
international
philosophy of mathematics seminar. My slides and a related
paper are available.
 During October 911, 2017 I visited the University of Munich and
gave the keynote address
at a
conference on reverse mathematics.
My slides and a paper are
available.
 During October 1114, 2017 I visited the University of Lisbon and
gave a talk at a
conference on the axiomatic method.
My slides and a paper are
available.
 On November 28 and December 4, 2017 I gave two talks on linear
lattices, in the
Universal
Algebra and Logic Seminar at Vanderbilt University.
My title
and abstracts are available.
 On February 19 and 29 and March 19, 2018 I gave three talks on
degrees of unsolvability, in the
Universal
Algebra and Logic Seminar at Vanderbilt University.
My title
and abstracts are available.
 During September 1114, 2018 I visited the University of Leeds and
gave a talk at a conference
in honor of Hermann Weyl's 1918 monograph Das Kontinuum.
My abstract and slides are
available.
 During May 2031, 2019 I visited the National University of
Singapore and gave a talk
at a workshop on
Higher Recursion Theory and Set Theory.
My slides are available
 During September 1520, 2019 I visited
the Casa Matemática
Oaxaca, in Oaxaca, Mexico, to participate and give a talk in
a workshop
on Reverse Mathematics.
My abstract and slides are
available
 On October 21 and 28, 2019 I gave two talks in the
Universal
Algebra and Logic Seminar
at Vanderbilt University.
My abstract and slides are
available.
 During June November 48, 2019 I visited the University of Barcelona
and gave an invited talk at a conference
on Proof
Theory, Modal Logic and Reflection Principles. My
abstract and slides are available.
 During June 1317, 2022 I virtually visited the University of
Paris 7 Diderot to participate in a virtual
Workshop on Reverse Mathematics
and its Philosophy. As part of the workshop I participated in a
virtual panel discussion.
My slides are available.
 During January 47, 2023 I attended the Joint Mathematics Meetings
in Boston, and gave an invited talk at an AMS Special Session in
honor of Gerald E. Sacks. My
slides are available.
Some of my publications are available.
t20@psu.edu / 20 January 2023