7 papers · 1 filter
The Cosmological Grassmannian
Mattia Arundine, Daniel Baumann, Mang Hei Gordon Lee +2
We introduce the orthogonal Grassmannian as a novel kinematic space for describing correlators of massless spinning fields in de Sitter space. By automatically encoding the constra…
Differential Equations for Massive Correlators
Daniel Baumann, Austin Joyce, Hayden Lee +1
We uncover a combinatorial structure governing the differential equations satisfied by wavefunction coefficients of scalar fields with generic masses in de Sitter space. Using an i…
Constraints on Long-Range Forces in De Sitter Space
Daniel Baumann, Kurt Hinterbichler, Callum R. T. Jones +4
The representation theory of de Sitter space admits partially massless (PM) particles, but whether such particles can participate in consistent interacting theories remains unclear…
Geometry of Kinematic Flow
Daniel Baumann, Harry Goodhew, Austin Joyce +3
We uncover a geometric organization of the differential equations for the wavefunction coefficients of conformally coupled scalars in power-law cosmologies. To do this, we introduc…
Kinematic Flow for Cosmological Loop Integrands
Daniel Baumann, Harry Goodhew, Hayden Lee
Recently, an interesting pattern was found in the differential equations satisfied by the Feynman integrals describing tree-level correlators of conformally coupled scalars in a po…
A New Twist on Spinning (A)dS Correlators
Daniel Baumann, Grégoire Mathys, Guilherme L. Pimentel +1
Massless spinning correlators in cosmology are extremely complicated. In contrast, the scattering amplitudes of massless particles with spin are very simple. We propose that the re…