Proof step

Laguerre’s theorem on differential operators

Image under a real-rootedness preserver derivative polynomial, shift 0

Concludes

one_plus_derivative of Triangle of second-order Eulerian numbers T(n,k) (n>=0, 0 <= k <= n) read by rows.

Premises

Triangle of second-order Eulerian numbers T(n,k) (n>=0, 0 <= k <= n) read by rows.
sequence: Every row P_n, n >= 1, is zero or real-rooted with all roots in (-inf, 0]

Theorem

[SP14] polytool ?

Lean

RealRooted RealRooted.splits_add_C_mul_derivative_all, RealRooted.splits_C_mul_add_derivative, Polynomial.Splits.derivative

Checked

polytool replayed · Lean not attempted

Technical details

Step id

e-06a6587f1ae52575 · JSON

Operation

Image under a real-rootedness preserver

{
  "index_shift": 0,
  "operation": "preserver_image",
  "operator": "{\"shape\":\"derivative_polynomial\",\"coefficients\":[{\"numerator\":[\"1\"],\"denominator\":[\"1\"]},{\"numerator\":[\"1\"],\"denominator\":[\"1\"]}]}"
}

Claims

{
  "claim": "real_rooted",
  "from_index": 1,
  "region": {
    "upper": {
      "closed": true,
      "value": "0"
    }
  }
}

{
  "claim": "interlacing",
  "from_index": 2,
  "kind": "weak",
  "orientation": "unordered"
}

Certificate

preserver_image, SHA-256 fc3bd2f0f2f6bf1783cc579ac69801643a940ae249df05926a5429f82eb23b8c, 15,599 bytes (3,616 compressed); download

polytool replayed the certificate when the step was written.

Cited by

n-17f334db6f3feea7 (one_signed_coefficients)
n-17f334db6f3feea7 (hadamard_kernel)
n-17f334db6f3feea7 (interlacing)
n-17f334db6f3feea7 (real_rooted)

References

[SP14] J Schur and G Polya. Über zwei Arten von Faktorenfolgen in der Theorie der algebraischen Gleichungen. J. Reine Angew. Math., 1914.