Topic: cosmological observables

Bring together amplitude-bootstrap approaches to string theory in flat and curved backgrounds. Researchers will discuss how bootstrap constraints reveal the structure of string amplitudes and how these methods extend to cosmological observables and anti-de Sitter or de Sitter settings. The workshop connects communities studying the S-matrix, cosmological correlators and quantum gravity through presentations and scientific discussion. 30 November 2026 at 09:00 through 4 December at 17:00, Asia/Taipei (UTC+8). Public participant registration closes on 20 November 2026.

Primordial fluctuations need not lose their quantum character as quickly as commonly assumed. Using inflationary effective theory beyond slow roll, this talk constructs Wigner functions whose negative interference fringes diagnose nonclassical behaviour. Those features can strengthen outside the horizon, and in some motivated regimes their creation outpaces environmental decoherence. The resulting phase-space structure suggests cosmological observables that might retain evidence of the fluctuations' quantum origins.