article published yes Michiel De Wilde author bebf1407-6635-11f0-9fef-9b7e2dd151d0 Robert Seiringer author 4AFD0470-F248-11E8-B48F-1D18A9856A870000-0002-6781-0521 RoSe department GradSch department We show that a suitable choice of boundary conditions for the Laplacian allows for the appearance of an arbitrary number of condensates, described by arbitrary harmonic functions, in the thermodynamic limit of an ideal Bose gas. AIP Publishing2026 eng 0022-2488 1089-7658 2601.2288310.1063/5.0325354 676 De Wilde, Michiel, and Robert Seiringer. “Arbitrary Harmonic Functions as Bose–Einstein Condensates.” <i>Journal of Mathematical Physics</i>, vol. 67, no. 6, 061901, AIP Publishing, 2026, doi:<a href="https://doi.org/10.1063/5.0325354">10.1063/5.0325354</a>. M. De Wilde, R. Seiringer, Journal of Mathematical Physics 67 (2026). De Wilde M, Seiringer R. 2026. Arbitrary harmonic functions as Bose–Einstein condensates. Journal of Mathematical Physics. 67(6), 061901. De Wilde, Michiel, and Robert Seiringer. “Arbitrary Harmonic Functions as Bose–Einstein Condensates.” <i>Journal of Mathematical Physics</i>. AIP Publishing, 2026. <a href="https://doi.org/10.1063/5.0325354">https://doi.org/10.1063/5.0325354</a>. De Wilde, M., &#38; Seiringer, R. (2026). Arbitrary harmonic functions as Bose–Einstein condensates. <i>Journal of Mathematical Physics</i>. AIP Publishing. <a href="https://doi.org/10.1063/5.0325354">https://doi.org/10.1063/5.0325354</a> M. De Wilde and R. Seiringer, “Arbitrary harmonic functions as Bose–Einstein condensates,” <i>Journal of Mathematical Physics</i>, vol. 67, no. 6. AIP Publishing, 2026. De Wilde M, Seiringer R. Arbitrary harmonic functions as Bose–Einstein condensates. <i>Journal of Mathematical Physics</i>. 2026;67(6). doi:<a href="https://doi.org/10.1063/5.0325354">10.1063/5.0325354</a> 222922026-07-13T09:45:09Z2026-07-13T12:20:59Z