Offering a very wide range of fee-based and free services to anyone needing assistance
with science, mathematics, and general computing.

Detailed information on services, software, ordering, and pricing can be obtained at:

Sunfreeware.com

One of my major projects is the Solaris Project at: unixpackages.com

This project and the previous sunfreeware.com project have had over 500,000 users and has been the hightest ranked and longest running (nearly 19 years) Solaris related project outside of Sun Microsystems/Oracle. Many of its users are the largest governmental, educational, research, business, financial, and military organizations in the world who use Solaris based systems.

In addition to the services of sunfreeware.com and unixpackages.com, I also offer paid consulting on any and all issues with respect to open source software on Solaris compatible systems. If you or your organization needrapid or very specialized assistance with Solaris software, contact me using the information above and I will provide a quote.

The Mathematica User Group

I founded and moderate the MathGroup mailing list which is linked to the moderated newsgroup

comp.soft-sys.math.mathematica

on the Internet. This group is used by many Mathematica users to exchange ideas and get technical support from a community of thousands of Mathematica experts. More than 85,000 messages have been posted to this very active group.

Contact your local system administrator to find out how to read this newsgroup.

Scientific Computing Software

I provide access to the following software packages and can assist in the selection and purchase of other advanced mathematics-related products:

MathTensor Tensor Analysis Software

MathTensor is a product of MathTensor, Inc. MathTensor's functions and objects for doing tensor analysis are listed on the MathTensor Functionality page.

For details on ordering MathTensor, go to the MathTensor home page.

For information on the book about MathTensor go to MathTensor: A System for Doing Tensor Analysis by Computer.

Very Large Scale Pattern Matching Problem in MathTensor A talk presented at the Mathematica Developer's Conference, October, 1995, Urbana, Illinois.

A paper by S.Christensen showing some applications of MathTensor in theoretical physics - Computational Challenges in Heat Kernel Calculations.

Other MathTensor related papers

Schur Group Theory Software

Schur is a powerful program for handling calculations with Lie and symmetric groups. It was created by the late Dr. Brian Wybourne.

Other Example Consulting Services

The following list of major projects done recently will give a good idea of the kind of work I can do. I also have many years of expertise in the selection and use of all levels of computer hardware and software (commercial and freeware). Some examples are:

SunSITE Project

Several years ago, I presented the concept of what now is called the SunSITE project to Sun Microsystem's Education and Research Group. With funding from them, I produced a project design and solicited proposals from major university Sun sites. I recommended the University of North Carolina Office of Information Technology as the first place to run such a project.

Because of its major and very quick success, other SunSITE projects were started by Sun around the world. Sun and the administrators at each SunSITE found many new ways to add value and interest to their local sites.

Cotton Incorporated Fiber Research

I was a contractor to the fiber research group at Cotton Incorporated's research facility in Raleigh, NC. I applied my knowledge of Mathematica to research in selection optimization problems, fiber and cloth visualization, noise filtering in time series yarn formation data, fluid flow, and other subjects. I also provided advice on hardware, software, and networking products and services, and assisting in the setting up of Web pages.

Protein Fragment Data Analysis

I designed a Mathematica program for a research group in the Biology Department at UNC-Chapel Hill. This program considers the problem of how to tell whether a given protein fragment can appear in the mass/charge ratio data from a mass spectrometer. In complicated experiments many hundreds of potential fragments might occur in many different charge or carboxylation states with or without disulfide links between certain fragment pairs. Given a mass/charge ratio number found in experimental data, the Mathematica program can identify which fragment or fragments linked together may appear with that value. An easy-to-use Mathematica notebook was created so that non-experts could use the package.

Reference letters and details can be supplied if requested.

Biographical Information

Steven M. Christensen, Ph.D.

Steve Christensen has many years of scientific research and computing experience. He began his computer interest building simple mechanical and vacuum tube logic circuits and by using analog and digital computers at the John Deere Research Center in Moline, Illinois as a high school student in the mid-1960's.

His high school research work was in nuclear magnetic resonance, optical pumping, and electro-optics. While an undergraduate in the Physics Department Augustana College in Rock Island, Illinois, he ran the college's computer center at night and trained students and faculty in computer languages, Galois theory, as well as teaching a year long special and general relativity course. His research interests changed to theoretical relativity and quantum mechanics. He began the use of computer algebra systems in 1968.

In graduate school at the University of Texas Center for Relativity, he did research with Bryce DeWitt (who sadly passed away in 2004) and fellow student Larry Smarr on black hole computer simulations and then moved to the study of quantum field theory in curved spacetimes and renormalization theory. In 2005, Dewitt was named the second recipient of the Einstein Prize.

As a postdoctoral fellow at King's College, London, The University of Utah, Harvard, and UC-Santa Barbara's Institute for Theoretical Physics, he worked closely with Stephen Fulling, Michael Duff, Paul Davies and others on black holes, cosmology, fourth order quantum gravity and anomalies.

Since 1980, as a professor at the Universities of North Carolina and Illinois, he has taught undergraduate and graduate courses in relativity, quantum field theory, and quantum gravity. In the 1990's, he formed MathSolutions, Inc. (now MathTensor, Inc.) with Leonard Parker and later formed Christensen and Associates, Inc. and Unix Packages LLC.

Send comments or questions to steve@smc.vnet.net

© Copyright 2013 Steven M. Christensen and Associates, Inc.
MathTensor is a Trademark of MathTensor, Inc.
Mathematica is a Registered Trademark of Wolfram Research, Inc.
This page was last updated on May 17, 2013