STEFFEN LEMPP

Address

Phone/Fax/Email

Office and office hours during semester

Courses taught in the fall semester 2008

• Math 130 - Lecture 2: Arithmetical Problem Solving: Course information
• Math 770: Foundations of Mathematics: Course information

Information for UW graduate students in math or with math minor

• UW math department information on graduate study
• UW math department qualifying exams
• UW Graduate School information on graduate study
• Requirements for a math minor (both for math graduate students and for graduate students in other departments)
• Requirements for a CS minor
• Requirements for a math Ph. D. student to get a master's degree in computer science
• Requirements for an education minor Requirements for a linguistics minor
• Requirements for a statistics minor
• Requirements for a finance minor

Logic seminars around the Midwest

• Southern Wisconsin Logic Colloquium
• Graduate Student Logic Seminar (GPS Logic), UW Math Department
• UW CS Theory Seminar
• University of Chicago Logic Seminar
• Chicago Joint Logic Seminar
• University of Illinois-Chicago Logic Seminar
• University of Illinois-Urbana Logic Seminar
• Notre Dame Logic Seminar
• Indiana University Logic Seminar

Conferences I plan to attend (and other times I will be out of town)

• October 11-12, 2008: Special Session on Computability Theory and Effective Algebra, AMS Sectional Meeting, Middletown, Conn.
• December 7-12, 2008: BIRS Workshop on "Computability, Reverse Mathematics and Combinatorics", Banff, Alberta
• May 20-23, 2009: ASL Annual Meeting, University of Notre Dame
• June 29-July 3, 2009: 4th Conference on Logic, Computability and Randomness, Marseilles, France
• May 23-28, 2010: Meeting in Algorithmic Randomness, University of Notre Dame

Other conferences of interest to logicians

• November 15-16, 2009: Midwest Model Theory Meeting, University of Notre Dame
• December 27-30, 2008: ASL Winter Meeting (joint with APA), Philadelphia
• January 4-9, 2009: NZIMA 2009 Summer Workshop in Algorithmic Information Theory, Computability and Complexity, Napier, New Zealand
• January 5-8, 2009: ASL Winter Meeting (joint with AMS/MAA/SIAM), Washington, D.C.
• May 18-22, 2009: Sixth Annual Conference on Theory and Applications of Models of Computation (TAMC'09), Changsha, China
• July 19-24, 2009: Computability in Europe 2009, Heidelberg, Germany
• July 31-August 5, 2009: ASL European Summer Meeting (Logic Colloquium '09), Sofia, Bulgaria
• August 24-28, 2009: Mal'tsev Meeting 2009, Novosibirsk

Travel Information on Madison and the University of Wisconsin

• Reaching Madison by air or airport limousine
• Reaching Madison by train or bus
• Reaching the UW campus by car
• Reaching UW campus area hotels by car
• UW campus map
• My favorite restaurants near the UW campus
• Greater Madison Convention and Visitors Bureau
• Madison area traffic cameras (provided by the Wisconsin Department of Transportation)
• Wisconsin Tourism Information
• Wisconsin Attractions (by Wisconline)
• Great Lakes Weather Radar

Travel information for foreign visitors to the UW math department

Since September 11, 2001, visa regulations for foreign visitors have become much stricter. In particular, the "wrong kind" of visa can result in

• your being denied a visa,
• your being denied entry at the border even if you have a visa or do not need a visa to enter the U.S. as a tourist,
• the department being unable to pay you any money for travel expenses, honorarium, consulting fees, or salary even if such payment was promised to you before, or
• your children being unable to attend public school in the U.S.

Here are some useful links:

State Department web sites on U.S. visas

• U.S. visa home page
• B1 visa information for short-term business visitors
• B2 visa information for tourists or persons accompanying short-term business visitors
• Visa Waiver Program (for citizens of many Western European and other industrialized countries, requires machine-readable passports)
• Visa information for citizens of Canada, Mexico and Bermuda
• J visa information for longer-term exchange visitors (J1 for visitors, J2 for dependents)
• List of U.S. Consulates worldwide

Related information for visitors

• Internal Revenue Service: U.S. federal taxes for foreigners
• "Traveling to the United States" information (by the U.S. National Academy of Sciences)
• SHIP Insurance: health insurance for international scholars at UW-Madison (including the Waiver Application Form)
• Social Security Administration: Individual Taxpayer Identification Number (ITIN) application
  
• UW information on immigration and tax restrictions
  
• UW International Faculty and Staff Services
• UW Math Department travel and visitor information
• UW tax information
• UW tax information for J-1 scholars
• Wisconsin Department of Revenue: Wisconsin state taxes (tax information brochure for non-residents)

My research interests

Some particular problems I am currently working on include

• algebraic structures of, and decidability of fragments of theories of, degree structures (esp. the c.e. Turing degrees, the d.c.e. and n-c.e. Turing degrees, and the Sigma⁰₂-enumeration degrees),
• lattice embeddings into the computably enumerable Turing degrees,
• computable linear orders and Boolean algebras,
• characterization of computable algebraic structures by classical invariants (e.g., Ketonen invariants and Ulm invariants),
• degrees of models of aleph₁-categorical theories, and more generally of trivial theories of finite Morley rank,
• proof-theoretical strength of Ramsey's Theorem for pairs and related combinatorial principles,
• equivalence of Martin-Löf randomness with other notions of randomness (in particular Kolmogorov-Loveland randomness).

My curriculum vitae and bibliography

• in postscript
• in pdf format

My publications on line

• Titles, abstracts, and postscript/pdf files

Transactions of the AMS and Memoirs of the AMS

Electronic submissions to the Transactions of the AMS or the Memoirs of the AMS must now be made on line, preferably indicating there the editor by whom the submission should be handled. Alternatively, hard copy submissions can be mailed to: Centralized Manuscript Processing, Transactions of the AMS (or Memoirs of the AMS), 201 Charles Street, Providence, RI 02904-2294, USA.

Prospective authors should note that the Transactions and the Memoirs receive many more submissions than can be published. Click here to view the letter I send to all referees.

Lecture Notes in Logic book series

The editors, Anand Pillay (managing editor, University of Leeds, England), Jeremy Avigad (Carnegie Mellon University), Shaughan Lavine (University of Arizona), Vladimir Kanovei (Institute for Information Transmission Problems, Moscow), Thomas Wilke (University of Kiel, Germany), and I, Steffen Lempp, invite book proposals from authors by email or postal mail.

Professional Organizations

• Association for Symbolic Logic (ASL)
• American Mathematical Society (AMS)
• Deutsche Mathematiker-Vereinigung (DMV)
• Deutsche Vereinigung für Mathematische Logik und für Grundlagen der Exakten Wissenschaften (DVMLG)
• American Philosophical Association (APA)
• Association for Computing Machinery (ACM)

Research databases of interest to logicians

• Algorithmic Randomness FRG (maintained by Rebecca Weber, Dartmouth
• AMS 2000 Mathematics Subject Classifications
• arXiv.org in logic (open-access database of papers in math and science, maintained by Cornell University)
• Bibliography on Boolean algebras (maintained by Don Monk, University of Colorado)
• Bibliography of Mathematical Logic and Related Fields ("Omega Bibliography") (under construction!, case sensitive search only, click on "Recherche", maintained by Heidelberger Akademie der Wissenschaften)
• Computability in Europe (CiE) (maintained by Barry Cooper, Leeds, England)
• Computability theory (maintained by Peter Cholak, Notre Dame)
• Computer Science Bibliography (maintained by the University of Trier, Germany)
• Copyright Page of the International Mathematical Union (maintained by Wilfrid Hodges, Queen Mary College, University of London)
• DigiZeitschriften (an open-access database of several free math journals from German-speaking countries, maintained by the University of Göttingen)
• Google's list "Logic and Foundations"
• JSTOR (Journal Storage, maintained by the Carnegie Mellon Foundation, requires subscription by your institution, or ASL membership)
• Lattice Drawing (maintained by Ralph Freese, University of Hawaii)
• Math-Net.Ru: All-Russian Mathematical Portal (maintained by Steklov Mathematical Institute of the Russian Academy of Sciences)
• Math journal price surveys (maintained by Ulf Rehmann, Bielefeld, Germany)
• Mathematical Logic around the world (maintained by Martin Goldstern, Technical University of Vienna, Austria)
• Mathematics Genealogy Project (supported by North Dakota State University)
• Mathematics on the Web (including foreign-language mathematical dictionaries, maintained by the AMS)
• MODNET, European Research Training Network in Model Theory
• Project Euclid (a non-profit journal database maintained by Cornell University and primarily funded by the Mellon Foundation)
• Research groups in logic and theoretical computer science (maintained by Anton Setzer, Swansea, Wales)
• Shelah Archive (maintained by Technical University of Vienna, Austria)

Job openings I happen to hear of

• Marie Curie Fellowships (funded by the European Union)
• National Security Agency
• University of Bern, Switzerland
• University of Leeds, England
• University of Wisconsin-Madison
• University of Wisconsin-Rock County, Janesville

Information on special Ph. D. Programs in Logic

• Carnegie-Mellon University, Pittsburgh, Pennsylvania
• Indiana University, Bloomington
• University of Amsterdam, Netherlands
• University of California-Berkeley
• University of Notre Dame

Information for Russian-speaking Logicians

I also administer the program of the Association for Symbolic Logic (ASL) offering

For more information about this program, click here for information in English or in Russian (KOI-8 encoding or Windows-1251 encoding).

Home pages of some other logicians

• Klaus Ambos-Spies, University of Heidelberg, Germany
• Andy Arana, Kansas State University, Manhattan, Kansas
• Marat Arslanov, Kazan State University
• Matthias Aschenbrenner, UCLA
• Jeremy Avigad, Carnegie Mellon University
• John Baldwin, University of Illinois-Chicago
• Verónica Becher, University of Buenos Aires
• Itaï Ben Yaacov, University of Lyon, France
• Michael Benedikt, Oxford University, England
• Vasco Brattka, University of Cape Town, South Africa
• Jin-Yi Cai, University of Wisconsin
• Doug Cenzer, University of Florida
• Peter Cholak, University of Notre Dame
• Chi Tat Chong, National University of Singapore
• Barry Cooper, University of Leeds
• Barbara Csima, University of Waterloo, Ontario, Canada
• Alf Dolich, Chicago State University
• Rod Downey, Victoria University of Wellington
• Mirna Džamonja, University of East Anglia, Norwich, England
• Peter Fejer, University of Massachusetts at Boston
• Harvey Friedman, Ohio State University
• Sergey Goncharov, Novosibirsk State University and Russian Academy of Sciences
• Valentina Harizanov, George Washington University
• Ward Henson, University of Illinois-Urbana
• Denis Hirschfeldt, University of Chicago
• Jeff Hirst, Appalachian State University, Boone, North Carolina
• Steve Jackson, University of North Texas
• Carl Jockusch, University of Illinois-Urbana
• Asher Kach, University of Connecticut-Storrs
• Bart Kastermans, University of Wisconsin-Madison
• Jerry Keisler, University of Wisconsin
• Tom Kent, University of Siena, Italy
• Bakhadyr Khoussainov, University of Auckland, New Zealand
• Byunghan Kim, Yonsei University, Seoul, South Korea
• Bjørn Kjos-Hanssen, University of Hawaii
• Peter Koepke, University of Bonn, Germany
• Ulrich Kohlenbach, University of Darmstadt, Germany
• Ken Kunen, University of Wisconsin
• Jean Larson, University of Florida
• Chris Laskowski, University of Maryland-College Park
• Andy Lewis, University of Leeds, England
• Jack Lutz, Iowa State University, Ames
• Dave Marker, University of Illinois-Chicago
• Joe Mileti, Dartmouth College
• Arnie Miller, University of Wisconsin
• Joe Miller, University of Wisconsin
• Russ Miller, Queens College, New York City
• Bill Mitchell, University of Florida
• Antonio Montalbán, University of Chicago
• Andrei Morozov, Novosibirsk State University and Russian Academy of Sciences
• Carl Mummert, University of Michigan
• Anil Nerode, Cornell University
• André Nies, University of Auckland, New Zealand
• Dag Normann, University of Oslo
• Anand Pillay, University of Leeds, England
• Andre Scedrov, University of Pennsylvania
• Sasha Shlapentokh, East Carolina University, Greenville, N.C.
• Richard Shore, Cornell University
• Steve Simpson, Pennsylvania State University
• Ted Slaman, University of California-Berkeley
• Bob Soare, University of Chicago
• Reed Solomon, University of Connecticut
• Andrea Sorbi, University of Siena, Italy
• Ivan Soskov, Sofia University, Bulgaria
• Patrick Speissegger, McMaster University, Hamilton, Ontario, Canada
• Frank Stephan, National University of Singapore
• Alexey Stukachev, Novosibirsk
• Lou van den Dries, University of Illinois at Champaign-Urbana
• Rebecca Weber, Dartmouth College
• Andreas Weiermann, Ghent University, Belgium
• Mariko Yasugi, Kyoto Sangyo University, Japan
• Liang Yu, Nanjing University, China
• Martin Ziegler, University of Freiburg, Germany
• Boris Zil'ber, University of Oxford, England