Verlinde (2016) has proposed a new modified theory of gravity, Emergent Gravity (EG), as an alternative to dark matter. EG reproduces the Tully-Fisher relationship with no free parameters, and agrees with the velocity curves of most massive, spiral galaxies well. In its current form, the theory only applies to isolated, spherically symmetric systems in a dark energy-dominated Universe, and thus can only be tested fairly with such systems. Here I develop equations for EG's velocity curve predictions given a realistic, extended mass distribution. I apply this to isolated dwarf galaxies. Then I test the predictions from EG versus the maximum velocity measurements of 81 isolated dwarf galaxies with projected shapes close to circular. I find that EG severely underpredicts the maximum velocities for those galaxies with measured velocities v>165 km/s. Most of these galaxies have greater HI gas masses than stellar masses, and it is seems that EG is unable to describe these systems well. Rotation curves of these isolated, HI gas-rich, nearly spherical dwarf galaxies would provide the definitive test of EG.

中文翻译：

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用孤立的矮星系测试紧急重力

Verlinde (2016) 提出了一种新的修正引力理论，即涌现引力 (EG)，作为暗物质的替代品。EG 在没有自由参数的情况下再现了 Tully-Fisher 关系，并且与大多数大质量螺旋星系的速度曲线非常吻合。以目前的形式，该理论仅适用于暗能量主导的宇宙中孤立的球对称系统，因此只能用此类系统进行公平测试。在这里，我开发了 EG 速度曲线预测的方程，给出了一个现实的、扩展的质量分布。我将此应用于孤立的矮星系。然后我测试了 EG 的预测与 81 个孤立矮星系的最大速度测量值，它们的投影形状接近圆形。我发现 EG 严重低估了那些具有测量速度的星系的最大速度 v> 165 公里/秒。大多数这些星系的 HI 气体质量大于恒星质量，EG 似乎无法很好地描述这些系统。这些孤立的、富含 HI 气体、近乎球形的矮星系的旋转曲线将提供对 EG 的最终测试。