README

This repository contains source code related to classifying the census of closed orientable 4-manifolds triangulated with up to six pentachora.

In order to run the code within this repo, you will need Regina 7.4 or newer, or a build from the Regina git repository.

Installation Instructions

1. Copy main.cc, boilerplate.h, and the census into a folder.
2. Open a terminal and navigate to the folder.
3. Type regina-helper makefile to build a makefile for your system.
4. Type make main to compile the main program.
5. Run the classification algorithm by typing ./main { CENSUS_FILE } [ -vTARGET_VERTICES ] [ -pTARGET_PENTACHORA ] where:
   • { CENSUS_FILE } is the path to a census file; and
   • v and p are optional parameters to set target vertices and pentachora respectively.
     By default TARGET_VERTICES is set to $\max(1,\chi(\mathcal{T}_0))$, where $\mathcal{T}_0$ is the first triangulation read from CENSUS_FILE, and $\chi(\mathcal{T_0})$ is the Euler characteristic of $\mathcal{T}_0$.
     Similarly TARGET_PENTACHORA is by default set to $|\mathcal{T}_0|$, i.e. the number of pentachora in $\mathcal{T_0}$.

Note that this algorithm works with edge degree isomorphism signatures and not regular isomorphism signatures. All of the census files in this repo have already been converted to edge degree iso sigs, so no conversion is required on these files. If you need to convert other (standard) isomorphism signature to edge degree signatures, use the T.isoSig_EdgeDegree() function in regina-python.

Happy classifying!