Higher dimensions and multiple universes are distinct concepts in theoretical physics. Higher dimensions can refer to spatial dimensions that exist outside our universe, which may help explain the universe's curvature, or to "curled-up" dimensions within the universe relevant to string theory. In contrast, multiple universes typically relate to the idea of our universe being one of many, potentially interacting with other "branes" or existing as different timelines in quantum theory. While higher dimensions may have no physical existence, some interpretations of multiple universes suggest they do. Understanding these distinctions is crucial for grasping the complexities of modern cosmology.
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