What the study found
The authors formulate and prove a synthetic Lorentzian Cartan-Hadamard theorem. They show that, under additional assumptions of global hyperbolicity and future one-connectedness, there is existence and uniqueness of timelike geodesics between any pair of timelike related points.
Why the authors say this matters
The study suggests this result transfers the corresponding statement from locally convex metric spaces to the Lorentzian setting and generalizes a smooth Lorentzian theorem to synthetic Lorentzian geometry. The authors also present it as a basis for a globalization result for non-negative upper timelike curvature bounds.
What the researchers tested
The researchers worked in the framework of Lorentzian (pre-)length spaces and Lorentzian length spaces. They used an appropriate notion of local concavity and then proved a globalization result for that concavity notion.
What worked and what didn't
Their local concavity approach allowed them to establish existence and uniqueness of timelike geodesics between timelike related points, given the stated assumptions. They also obtained a globalization statement for non-negative upper timelike curvature bounds. The abstract does not report any failed cases or negative results.
What to keep in mind
The stated geodesic result depends on the additional assumptions of global hyperbolicity and future one-connectedness. The abstract does not describe limitations beyond these assumptions.
Key points
- The paper proves a synthetic Lorentzian Cartan-Hadamard theorem.
- It extends a result from locally convex metric spaces to the Lorentzian setting.
- It generalizes a smooth Lorentzian theorem to synthetic Lorentzian geometry.
- Under global hyperbolicity and future one-connectedness, timelike geodesics exist uniquely between timelike related points.
- The authors also derive a globalization result for non-negative upper timelike curvature bounds.
Disclosure
- Research title:
- Synthetic Lorentzian Cartan-Hadamard theorem established
- Authors:
- Darius Erös, Sebastian Gieger
- Publication date:
- 2026-04-22
- OpenAlex record:
- View
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