Null Field and Interior Field Methods for Laplace’s Equation in Circular Domains with Very Small Holes 李明恭,黃宏財,李子才,游坤明 Leisure and Recreation Management Tourism mglee@chu.edu.tw Abstract For solving Laplace's equation in circular domains with circular holes, the null field method (NFM) was developed by Chen and his research group (see \cite{CS2009}). In \cite{LLHL2010} the explicit algebraic equations of the NFM were provided, where some stability analysis was made. For the NFM, the conservative schemes were proposed in \cite{LLHC2013}, and the algorithm singularity was fully investigated in \cite{LLZHC2013}. To target on the same problems, a new interior field method (IFM) was developed in \cite{HLLC2013}. In addition to the NFM and the IFM, the collocation Trefftz method (CTM) is also an effective boundary method. %This paper is devoted to a further study on NFM and IFM. The goal of this paper is to apply those methods to Laplace's equation in the circular domains with extremely small holes, which is also named as actually punctured disks in this paper. By NFM, IFM, and CTM, numerical experiments are carried out, and comparisons are provided. Keyword:Null field method, collocation Trefftz method, small holes, Interior field method