\[\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}\]
\frac{1}{\sqrt{k}} \cdot {\left(\left(2 \cdot \pi\right) \cdot n\right)}^{\left(\frac{1 - k}{2}\right)}
(FPCore (k n)
 :precision binary64
 (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))
double code(double k, double n) {
	return (1.0 / sqrt(k)) * pow(((2.0 * ((double) M_PI)) * n), ((1.0 - k) / 2.0));
}

Reproduce

Please include this information when filing a bug report:

herbie shell --seed 2021060 
(FPCore (k n)
  :name "Migdal et al, Equation (51)"
  :precision binary64
  (* (/ 1.0 (sqrt k)) (pow (* (* 2.0 PI) n) (/ (- 1.0 k) 2.0))))

Backtrace

Failed to produce proof for (+.f64 (-.f64 (-.f64 (*.f64 (log.f64 2) (/.f64 1 2)) (*.f64 (log.f64 2) (/.f64 k 2))) 0) (-.f64 (*.f64 (log.f64 (*.f64 n PI.f64)) (/.f64 1 2)) (+.f64 (log.f64 (sqrt.f64 k)) (*.f64 (log.f64 (*.f64 n PI.f64)) (/.f64 k 2))))) to (-.f64 (+.f64 (*.f64 (log.f64 2) (-.f64 (/.f64 1 2) (/.f64 k 2))) (/.f64 (log.f64 (*.f64 n PI.f64)) 2)) (log.f64 (*.f64 (sqrt.f64 k) (pow.f64 (*.f64 n PI.f64) (/.f64 k 2)))))LC
for-loop/data/pavpan/nightlies/herbie/egg-generate-proof/src/core/simplify.rkt1678
(unnamed)/data/pavpan/nightlies/herbie/egg-generate-proof/src/core/simplify.rkt1496
egraph-add-exprs/data/pavpan/nightlies/herbie/egg-generate-proof/egg-herbie/main.rkt1540
with-egraph/data/pavpan/nightlies/herbie/egg-generate-proof/egg-herbie/main.rkt740
(unnamed)/data/pavpan/nightlies/herbie/egg-generate-proof/src/core/simplify.rkt790
simplify!/data/pavpan/nightlies/herbie/egg-generate-proof/src/mainloop.rkt2360
run-iter!/data/pavpan/nightlies/herbie/egg-generate-proof/src/mainloop.rkt3600
for-loop/data/pavpan/nightlies/herbie/egg-generate-proof/src/mainloop.rkt3912
run-improve/data/pavpan/nightlies/herbie/egg-generate-proof/src/mainloop.rkt3770
(unnamed)/data/pavpan/nightlies/herbie/egg-generate-proof/src/sandbox.rkt546
run/opt/racket-7.9/share/pkgs/profile-lib/main.rkt392
profile-thunk/opt/racket-7.9/share/pkgs/profile-lib/main.rkt90
(unnamed)/opt/racket-7.9/collects/racket/engine.rkt4224