Table 1 The Euler characteristic of \(\:{B}_{N}\) and \(\:{B}_{N}-{E}_{N,m}\) and computed using our method, with calculated values shown in parentheses for precision. * and denote the \(\:N\)-dimensional ball and spherical shell, respectively. For the 4-dimensional case, additional 2D manifolds embeddable in 4D space, the real projective plane (\(\:\text{R}{\text{P}}^{2})\) and the Klein bottle, are included.

From: Computing Euler characteristic of \({N}\)-dimensional objects via a Skyrmion-inspired overlaying (\({N}\)+1)-dimensional chiral field

\(N=2\)

 
 

\(\:{B}_{2}\)

\(\:{B}_{2}-{E}_{\text{2,1}}\)

\(\:{B}_{2}-{E}_{\text{2,2}}\)

 

\(\:n\)

1 (0.999)*

2 (1.999)

0 (0.000)

 

\(N=3\)

 
 

\(\:{B}_{3}\)

\(\:{B}_{3}-{E}_{\text{3,1}}\)

\(\:{B}_{3}-{E}_{\text{3,2}}\)

\(\:{B}_{3}-{E}_{\text{3,3}}\)

 

\(\:n\)

1 (0.999)*

2 (1.999)

0 (0.000)

2 (1.999)

 

\(N=4\)

 
 

\(\:{B}_{4}\)

\(\:{B}_{4}-{E}_{\text{4,1}}\)

\(\:{B}_{4}-{E}_{\text{4,2}}\)

\(\:{B}_{4}-{E}_{\text{4,3}}\)

\(\:{B}_{4}-{E}_{\text{4,4}}\)

\(\:\text{R}{\text{P}}^{2}\)

Klein Bottle

\(\:n\)

1 (0.999)*

2 (1.999)

0 (0.000)

2 (1.997)

0 (0.005)

1 (0.993)

0 (0.000)