Irrationality of the dilogarithm at
Abstract.
We prove that is irrational. Irrationality of was known for integers and by work of Hata and of Rhin and Viola, and Prellberg recently proved it for . We define polynomials with rational coefficients by an interpolation determinant. The rank of this determinant modulo primes with bounds the denominators of the coefficients. A concavity inequality for a logarithmic energy bounds . The only interval-arithmetic step is the potential certificate. The exact data in Table A.1, the coefficients of , and the determinant modulo are printed and hand-checkable. A congruence modulo shows that has no rational zero for .
Key words and phrases:
dilogarithm, irrationality, interpolation determinant, vector equilibrium, Padé approximation2020 Mathematics Subject Classification:
Primary 11J72; Secondary 33B301. Introduction
For let . Hata [3, Theorem 1.1] proved that is irrational for every integer and every . Rhin and Viola settled by their permutation group method [7, Section 6], and later treated negative arguments [8, Theorem 2.1 and Section 4]. Viola and Zudilin [10] introduced a six-parameter family of double integrals for dilogarithmic values. In 2024 Calegari, Dimitrov and Tang [1, Remark 2.8.2 and Section 15.2] listed the integers still open: . Prellberg’s 2026 preprint [6, Theorem 1.1] proves the cases . We prove the case .
Theorem 1.
The number is irrational.
2. The determinant
Put . For let
all ordered increasingly. For put
For , and let
and put
| (2.1) |
a determinant of size . For an indeterminate the same formulas define
Lemma 2.1.
One has , , and
| (2.2) |
Proof.
Write and
Polynomial division and the geometric series give
The substitution gives
Hence the first identity in (2.2). Add times each row to the corresponding row of . Only the middle rows depend on , and their coefficients are rational. ∎
Put and
With the real intervals oriented increasingly, let
a linear combination of paths. For every integer ,
| (2.3) |
For integrate on each path. For the real intervals give and the arcs give .
For put . Use variables , and .
Lemma 2.2.
With product differentials ,
| (2.4) |
where
Proof.
By (2.3), . Put . Then
Set and . Multilinearity in the rows and antisymmetrization, applied to the rows , then to the rows , and then to the functions , give
where
The last equality follows from the Cauchy–Vandermonde identity. Explicitly, for ,
The Cauchy–Vandermonde identity is
This is the Cauchy–Vandermonde identity [4]. With the preceding row-scaling identity it gives the displayed formula for , and continuity covers . We verify the identity by induction on . At the induction step fix , let , and let denote with omitted. After multiplying by , the residue of the quotient at is
By induction this is the signed complementary minor on the determinant side, so the residues agree. After subtracting them, the difference is a polynomial in of degree at most and vanishes at the other variables . For it tends to zero at infinity. The case is the Vandermonde identity.
The product of the four factors is . Since , both signs are positive and . ∎
3. The divisor
Put
For let .
Lemma 3.1.
For an indeterminate ,
| (3.1) |
Proof.
The denominators of a entry divide . An off-diagonal entry is a difference of harmonic sums divided by , so its denominator divides , and so does that of . The denominators of a entry divide . ∎
3.1. Residue classes
For and let
| (3.2) | ||||
and
| (3.3) |
Lemma 3.2.
Let be an odd prime with , and let . Then
| (3.4) |
Proof.
Multiply the rows by . Write , with . Only the harmonic terms with in the denominator survive modulo , and , so
The scaled and entries vanish modulo between distinct residue classes modulo . For a cross-class entry, the numerator is -integral after the row scaling and the remaining factor is zero modulo . Within a class, for , with , so the quotient denominator is a unit. Diagonal entries have their displayed separate values. Thus within a class they reduce to and , and . A row reduces to zero unless . Then its entry is , without the factor . All displayed denominators are units because . So, after permutations, the reduction has blocks with rows and columns.
For , , the block, with its rows divided by the unit , is
| (3.5) |
of rank one for every odd . Every other block has rank at most the minimum of its dimensions. So the rank is at most . The matrix has rows. Row operations over , independent of , make its last rows divisible by . Subtracting the scaling exponent gives the first inequality in (3.4).
Every boundary in (3.2) has the form with . At , , it lies in . The conditions are closed on the left and open on the right in , and the condition is . So is constant on each , and
| (3.6) |
For only , and occur. The sets in (3.2) change only on the lines
| (3.7) |
Cut at the values of where two of these lines meet in , and let be the set of these cut points. On each resulting interval the order of the lines in is fixed, so the sets (3.2) are constant on each -interval between consecutive lines, and is affine. At both endpoints of each row, its five printed lines , in their printed order, satisfy
Every other distinct line in (3.7) is at both endpoints or at both endpoints. Affineness and distinctness make the ordering strict in the interior, apart from boundary lines. Hence no intersection in is omitted. Table A.1 lists the intervals, the five lines in in increasing order, the values of on the six -intervals, and . Each row can be checked by hand from (3.3). The table was also rechecked in exact rational arithmetic (Appendix F). Summation gives
| (3.8) |
The configuration of (3.5) occupies for , and for . Its contribution to (3.8) is
3.2. Larger primes
For define row potentials , , and column potentials by
and put
Lemma 3.3.
For an odd prime one has .
Proof.
A entry has a pole only at , of order at most one. A entry has pole order at most
including the double pole of for . A entry has a simple pole when . As , there are no higher powers.
In the first range every row has potential at least one, and two if . A collision has , and its column gives the second unit. In the second range all . The columns cover the simple poles and the poles. A collision needs , and its row gives the other unit. In the third range and , so only simple poles remain. In these three ranges every row has potential one, which covers and . In the fourth range , only poles remain, and the rows with are those containing one. So dominates every pole order. Multiply each row and column by to the power of its potential. The potentials add up to , , and in the four ranges. ∎
3.3. The factor at two
Lemma 3.4.
Let . Then
| (3.9) |
Proof.
Work in . Write
Subtract times each row from the paired row of . Comparison of coefficients, including the diagonal, gives
| (3.10) | ||||
For example, the off-diagonal lower entry is , and the diagonal entry is . Each coefficient of involves finitely many terms.
Expand along the rows of , and expand each remaining -row minor by the rank-one summands in (3.10). A nonzero term selects distinct rank-one summands. At weight at most
occur: the first summand needs , the third needs . All entries, including , have nonnegative order in . So every term has order at least the sum of the smallest available weights. This use of the infinite expansion is coefficientwise: modulo only finitely many occur, so Cauchy–Binet applies to a finite truncation and then gives the asserted formal divisibility.
3.4. Summation over primes
Lemma 3.5.
For every , there is a rational number with and
so that .
Proof.
Put . For odd , with the first line taking precedence, let
| (3.11) |
and
By (3.6), . Lemmas 3.1, 3.2, 3.3 and 3.4 give for every . The exponent at two may be negative.
For all sufficiently large , implies . Put
By the prime number theorem, . For an affine on , Stieltjes integration by parts gives
There are finitely many pieces, and the excluded primes at cut points contribute . For the first powers contribute , and the higher powers, including those of two,
Subtract once. For the exponent is with
With (3.8),
The total error is . ∎
4. Analytic estimate
In (2.4) there are , and variables , , . Let
For , let
The sets avoid zero, and is bounded on . For positive measures of masses put
For a fixed let , , and
Lemma 4.1.
On triples of positive measures of masses with finite absolute logarithmic self-integrals and , , and , respectively, the functional is concave. The same statement applies when all supports lie in the smaller sets .
| (4.1) |
Proof.
For positive compactly supported measures in a disk strictly containing their supports, the Green kernel of is plus a bounded term. Cauchy–Schwarz for its energy, together with the finite absolute self-integrals, gives absolute logarithmic cross-integrability. Thus signed differences of the measures used below have finite absolute logarithmic energy.
For a real signed measure of mass zero, with positive compactly supported parts of finite absolute logarithmic self-integrals, write for the sign convention in Saff–Totik. Their positivity lemma [9, Lemma I.1.8] gives
For smooth , the identity
follows from and integration by parts. The boundary term vanishes because the mass is zero. Approximation extends this Dirichlet-integral formula to the stated finite-energy measures. Put .
Let have mass zero in each coordinate, and first let the -support avoid zero. Put . Then
and the one-variable terms integrate to zero. With , and ,
The -supports here avoid zero. In general fix a probability with smooth density supported in , and put
It has mass zero and support away from zero, so . Finite energy excludes an atom at zero, so the coefficient of tends to zero as . The cross-integrability just proved makes the logarithmic kernels integrable against the total variations, and the potential of is bounded on compact sets. Dominated convergence in the original coordinates gives
The kernel is bounded on the sets specified above. For the reference and the smoothed measures below also : the reference has bounded interval density, and the smoothed measures stay away from zero. With
and the first kernel identity, dominated convergence also applies to the inverted pairings.
Expand with . The quadratic part is nonpositive and . Adding the linear terms gives (4.1). ∎
Lemma 4.2 (computer-assisted).
Proof.
The rational data of are printed in Tables D.1 and D.2. An interval of mass carries . A Poisson entry , , is
The file anc/analytic/reference.json repeats these tables for the verification program. The weights are positive, the three masses are exact, and the Poisson entries are invariant under conjugation. An interval has potential
with on the real line. A Poisson entry has potential
| (4.3) |
Let denote the Poisson contribution to the -potential. Put
Since , the 157 Poisson rows give
Real interval energies use , with . For the denominator,
The pair decomposition and its outward enclosures are printed in Table C.1. Since the product mass of is , the integrated remainder is at most
The bounds for are proved by subdivision in Arb ball arithmetic [5]. On a real subinterval, each interval-potential component is quasi-convex: away from , its derivative has the sign of , which changes from negative to positive at , while the negative denominator term is convex. On each side of a Poisson-entry potential is the logarithm of the distance from to a fixed point, hence quasi-convex, and a row containing also evaluates . Thus the component maximum is bounded by the relevant endpoint values. On a subarc of the circle, the largest distance to a pole is at an endpoint or at the antipodal point. Interval sign tests exclude the antipodal point when possible. If it lies on the subarc, or if a sign test is inconclusive, the full-circle upper bound is used. Otherwise the endpoint values suffice. Table B.1 covers the real paths and the upper semicircle, and conjugation covers the lower one. On the subintervals meeting zero the positive term or is increasing in and equals at zero. For a real pole and , . This is monotone in for each fixed sign of , which justifies the endpoint or antipodal alternatives.
On use , and with the same primitives. This gives (4.2). An interval has density . With respect to arclength, a Poisson entry has density at most
| (4.4) |
The endpoint majorants and disk bounds are printed in Table C.2 and the density checks in Table C.3. The density checks are rational, by an integer square-root bound for each and by , which follows from Machin’s formula:
Lemma 4.3.
Put . If , then
Proof.
Let be a measurable set of measure containing the real support. By the triangle inequality,
Replacing or by its real part increases each integral. Symmetric decreasing rearrangement gives
so
by . The interval components have disjoint interiors, so multiply by the density bound. By (4.3), a Poisson component is Lipschitz with constant at most , and by (4.4)
Summation and give the bound for . ∎
Lemma 4.4.
If , then
Proof.
Expand in (2.4) into products of its four oriented pieces. On each piece use normalized arclength, and keep its coefficient and tangent phase until taking absolute values. Since , the absolute weights add up to
so the paths contribute a factor at most . Only positive measures enter Lemma 4.1.
Put and . Replace every atom by the uniform measure of mass on the circle . The resulting have masses and finite energy. The common translation preserves differences, so by subharmonicity in each variable averaging increases every positive logarithmic pair. Each circle has energy , so removing the diagonal adds
The positive endpoint terms also increase, since
| (4.5) |
If an original factor vanishes, there is nothing to prove.
For the negative kernels satisfy the derivative bounds
| (4.6) |
since a displacement of at most in each coordinate gives and . So the negative terms contribute at most
Discard the factorials and in (2.4). Then the logarithm of the integrand, with its prefactor, is at most
| (4.7) |
We bound the three fields in (4.1) on the smoothed measures. Put . Lemma 4.3 with gives the coefficients
and a weighted error at most .
For an or center the whole circle lies in , where (4.2) applies. Otherwise , and (4.5) gives
So the positive terms add at most . By (4.6), the negative terms in the three fields add at most . At , and hence for all larger ,
So the total smoothing error is at most . Insert the lower endpoint of (B.1) in (4.1). As
we get . With (4.7) and the path factor,
Divided by , no positive term increases for . At their sum is
5. Nonvanishing
Let , and let be the -adic valuation, .
Lemma 5.1.
For ,
| (5.1) |
and has no root in .
Proof.
| 0 | 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | |
| 4 | 3 | 6 | 3 | 2 | 7 | 7 | 9 | 5 | 5 | 4 |
Lemma 5.2.
For every and every integer , .
Proof.
Put , and , and
| (5.3) |
This is the determinant obtained after by multiplying the , and rows by , and . Every nonzero index, difference and Cauchy denominator has absolute value less than , hence -adic valuation at most . So , and all entries of the scaled matrix lie in . Hence and .
Let and . Only the summation indices divisible by survive, and , so
The scaled and entries vanish modulo between distinct residue classes modulo . In the class write , . Then and . The only row in this class is , with
Cross-class and entries have -adic valuation at least . Within a class the nonzero differences satisfy and are units. All other scaled entries vanish modulo . So, after permutations, the matrix has diagonal blocks
where the subscript refers to . Each block has eight rows with the factor . Hence
| (5.4) |
The constant coefficient and the coefficient of are -adic units, and .
6. Proof of Theorem 1
Appendix A Arithmetic integration
In Table A.1 the second column lists the lines (3.7) in , in increasing order of . The third column lists on the six -intervals they cut from . Then . In the last three rows the fifth value includes the correction of (3.3). By (3.11), the values of at the cut points are not used. Of the lines (3.7), meet for some , and meet the closed interval after adding and . The table has regions and distinct triples .
| lines in | ||||
|---|---|---|---|---|
| sum | |||||
| contribution of (3.5) |
Appendix B Numerical values
The bounds in Table B.1 are rounded upward. The rational enclosures are
| (B.1) | ||||
| (B.2) | ||||
the lower bound for holds with in place of .
| support | subintervals | depth | upper bound | |
|---|---|---|---|---|
| 1164 | 15 | |||
| 1272 | 16 | |||
| 658 | 14 | |||
| 4 | 2 | |||
| 693 | 11 |
Appendix C Printed interval data
Tables C.1–C.3 give the numerical enclosures used in Lemma 4.2. Every displayed interval is outward rounded. The static row checks compare each upper endpoint with the printed bound.
Here is the energy of the real part of , the cross term
of its real and Poisson parts, and the Poisson self-energy.
includes both the real and Poisson parts of .
term
outward enclosure
[-1.546417482857900440,
For put , and put . Put
Then for and . For the displayed endpoint calculation reads
The denominator expansion retains terms. Since and the total – mass is , the integrated remainder is bounded by
| quantity | outward enclosure |
|---|---|
|
[-0.638636770206138024, |
|
|
[-1.118528621477847036, |
|
|
[0.148575311504214922, |
|
|
[-0.333515904969252, |
|
| (sum of the 157 Poisson weights) | 26460009509/40000000000 |
|
[0.691145177889270, |
|
|
[0.863931472361588, |
|
|
[-6.28230070117056, |
|
|
[-4.49350824377558, |
| support | exact maximum used | integer upper bound |
|---|---|---|
| real | ||
| circle | by the integer square-root and checks |
Appendix D Reference measure data
The two tables specify the reference measure . All entries are exact terminating decimals.
Table D.1 lists the intervals of on each real support in increasing order of the index, and each line holds two consecutive entries (odd index left, even index right). Entry is the interval carrying , where is the of the entry with the next index in the same block. The last of each block is given in its heading. Outside these intervals has no mass. For example, vanishes on .
Table D.2 lists the circular part of . Every row is a measure on the circle , whose upper half is the support of Appendix E. It is the Poisson measure of the proof of Lemma 4.2 with center , , and total mass . Its logarithmic potential is (4.3). The - and -parts of have no Poisson rows.
| index | index | ||||
|---|---|---|---|---|---|
| -intervals on : rows 1–50, last right endpoint . | |||||
| 1 | 0.02653493525245 | 0.000000000011 | 2 | 0.03806023374436 | 0.000000000056 |
| 3 | 0.05156362923366 | 0.000000000066 | 4 | 0.06698729810778 | 0.009047636046 |
| 5 | 0.08426519384873 | 0.016164978747 | 6 | 0.10332332985438 | 0.019034345994 |
| 7 | 0.12408009626051 | 0.021065372172 | 8 | 0.14644660940673 | 0.022447569912 |
| 9 | 0.17032709244997 | 0.02345382024 | 10 | 0.19561928549564 | 0.024200308115 |
| 11 | 0.2222148834902 | 0.02476625456 | 12 | 0.25 | 0.025199538621 |
| 13 | 0.2788556548905 | 0.02553284359 | 14 | 0.30865828381746 | 0.025790757407 |
| 15 | 0.33928026734842 | 0.02598943694 | 16 | 0.37059047744874 | 0.026140976998 |
| 17 | 0.40245483899194 | 0.026255972454 | 18 | 0.43473690388997 | 0.026341379215 |
| 19 | 0.46729843538493 | 0.026402361973 | 20 | 0.5 | 0.026444293432 |
| 21 | 0.53270156461507 | 0.026470882322 | 22 | 0.56526309611003 | 0.026484444361 |
| 23 | 0.59754516100806 | 0.026487798034 | 24 | 0.62940952255126 | 0.026483565514 |
| 25 | 0.66071973265158 | 0.026473037339 | 26 | 0.69134171618254 | 0.026457122002 |
| 27 | 0.7211443451095 | 0.026437395821 | 28 | 0.75 | 0.026415300265 |
| 29 | 0.7777851165098 | 0.026391297706 | 30 | 0.80438071450436 | 0.026365737946 |
| 31 | 0.82967290755003 | 0.026339451805 | 32 | 0.85355339059327 | 0.026313133347 |
| 33 | 0.87591990373949 | 0.026286966515 | 34 | 0.89667667014562 | 0.026260716757 |
| 35 | 0.91573480615127 | 0.02623413097 | 36 | 0.93301270189222 | 0.026207204488 |
| 37 | 0.94843637076634 | 0.026178707612 | 38 | 0.96193976625564 | 0.026146051892 |
| 39 | 0.97346506474755 | 0.026100427024 | 40 | 0.98296291314453 | 0.026045558902 |
| 41 | 0.99039264020162 | 0.025800471869 | 42 | 0.99572243068691 | 0.02600510817 |
| 43 | 0.9989294616193 | 0.00101387447 | 44 | 0.9989702065603 | 0.001749595019 |
| 45 | 0.99908623833539 | 0.002577120956 | 46 | 0.99925989215865 | 0.003342459833 |
| 47 | 0.99946473080965 | 0.004008718139 | 48 | 0.99966956946065 | 0.004554823645 |
| 49 | 0.99984322328391 | 0.004774398867 | 50 | 0.999959255059 | 0.005316651861 |
| -intervals on : rows 51–102, last right endpoint . | |||||
| 51 | 0.00960735979838 | 0.013858434309 | 52 | 0.01703708685547 | 0.020659018632 |
| 53 | 0.02653493525245 | 0.022756374414 | 54 | 0.03806023374436 | 0.024040451088 |
| 55 | 0.05156362923366 | 0.024796480607 | 56 | 0.06698729810778 | 0.025298366124 |
| 57 | 0.08426519384873 | 0.025649764501 | 58 | 0.10332332985438 | 0.025910099392 |
| 59 | 0.12408009626051 | 0.026113452847 | 60 | 0.14644660940673 | 0.02628122952 |
| 61 | 0.17032709244997 | 0.026427269003 | 62 | 0.19561928549564 | 0.026561515238 |
| 63 | 0.2222148834902 | 0.026691316341 | 64 | 0.25 | 0.026821861266 |
| 65 | 0.2788556548905 | 0.026957166859 | 66 | 0.30865828381746 | 0.027100366588 |
| 67 | 0.33928026734842 | 0.027253308259 | 68 | 0.37059047744874 | 0.027416681441 |
| 69 | 0.40245483899194 | 0.027590343833 | 70 | 0.43473690388997 | 0.027773157352 |
| 71 | 0.46729843538493 | 0.027962829423 | 72 | 0.5 | 0.028155382615 |
| 73 | 0.53270156461507 | 0.028348951325 | 74 | 0.56526309611003 | 0.028512049639 |
| 75 | 0.59754516100806 | 0.028704024914 | 76 | 0.62940952255126 | 0.02895179599 |
| 77 | 0.66071973265158 | 0.029147228949 | 78 | 0.69134171618254 | 0.029330189043 |
| 79 | 0.7211443451095 | 0.029497893354 | 80 | 0.75 | 0.029651492159 |
| 81 | 0.7777851165098 | 0.029791323098 | 82 | 0.80438071450436 | 0.029918006281 |
| 83 | 0.82967290755003 | 0.030031872164 | 84 | 0.85355339059327 | 0.030133175201 |
| 85 | 0.87591990373949 | 0.030222548301 | 86 | 0.89667667014562 | 0.030300285976 |
| 87 | 0.91573480615127 | 0.030366116749 | 88 | 0.93301270189222 | 0.030419889284 |
| 89 | 0.94843637076634 | 0.030460392026 | 90 | 0.96193976625564 | 0.030485017656 |
| 91 | 0.97346506474755 | 0.030483706899 | 92 | 0.98296291314453 | 0.030461131797 |
| 93 | 0.99039264020162 | 0.030205136068 | 94 | 0.99572243068691 | 0.030465558928 |
| 95 | 0.9989294616193 | 0.001188270853 | 96 | 0.9989702065603 | 0.002050223725 |
| 97 | 0.99908623833539 | 0.003019909346 | 98 | 0.99925989215865 | 0.003916871095 |
| 99 | 0.99946473080965 | 0.004697775042 | 100 | 0.99966956946065 | 0.005337916652 |
| 101 | 0.99984322328391 | 0.005595394787 | 102 | 0.999959255059 | 0.006230983047 |
| -intervals on : rows 103–164, last right endpoint . | |||||
| 103 | -2 | 0.002445904785 | 104 | -1.9999429570826 | 0.002196289941 |
| 105 | -1.99978051259747 | 0.002095070288 | 106 | -1.99953739724491 | 0.001843711398 |
| 107 | -1.99925062313351 | 0.001537127441 | 108 | -1.99896384902211 | 0.001185108178 |
| 109 | -1.99872073366955 | 0.000804636229 | 110 | -1.99855828918442 | 0.000466572663 |
| 111 | -1.99850124626702 | 0.011949094627 | 112 | -1.99401140296167 | 0.011829831253 |
| 113 | -1.98654969628226 | 0.011904636078 | 114 | -1.97614807840235 | 0.011879377704 |
| 115 | -1.96285109064657 | 0.011837079332 | 116 | -1.9467156727579 | 0.01177589427 |
| 117 | -1.92781091907288 | 0.011699589994 | 118 | -1.90621778264911 | 0.011609193707 |
| 119 | -1.88202872861178 | 0.011505113623 | 120 | -1.85534733820386 | 0.011387043787 |
| 121 | -1.82628786523528 | 0.011255100131 | 122 | -1.79497474683058 | 0.011109018301 |
| 123 | -1.76154207057005 | 0.010947966233 | 124 | -1.7261330003061 | 0.01077167805 |
| 125 | -1.68889916311372 | 0.010579949336 | 126 | -1.65 | 0.010372009648 |
| 127 | -1.6096020831533 | 0.010147136288 | 128 | -1.56787840265556 | 0.009904930406 |
| 129 | -1.52500762571221 | 0.009644863536 | 130 | -1.48117333157176 | 0.009366270662 |
| 131 | -1.43656322541129 | 0.009068614306 | 132 | -1.39136833455404 | 0.00875137721 |
| 133 | -1.3457821904611 | 0.008414043831 | 134 | -1.3 | 0.008056385332 |
| 135 | -1.2542178095389 | 0.007678505629 | 136 | -1.20863166544596 | 0.007280632319 |
| 137 | -1.16343677458871 | 0.006863145229 | 138 | -1.11882666842824 | 0.006426779891 |
| 139 | -1.07499237428779 | 0.005972788018 | 140 | -1.03212159734444 | 0.005503141876 |
| 141 | -0.9903979168467 | 0.00502059841 | 142 | -0.95 | 0.004528595244 |
| 143 | -0.91110083688628 | 0.004031298216 | 144 | -0.8738669996939 | 0.00353382249 |
| 145 | -0.83845792942995 | 0.003042591462 | 146 | -0.80502525316942 | 0.002564906577 |
| 147 | -0.77371213476472 | 0.002108555487 | 148 | -0.74465266179614 | 0.001681749548 |
| 149 | -0.71797127138822 | 0.001293146877 | 150 | -0.69378221735089 | 0.000950929581 |
| 151 | -0.67218908092712 | 0.000661669911 | 152 | -0.6532843272421 | 0.000429830492 |
| 153 | -0.63714890935343 | 0.000257484313 | 154 | -0.62385192159765 | 0.000143377053 |
| 155 | -0.61345030371774 | 0.000084543242 | 156 | -0.60598859703833 | 0.000061123507 |
| 157 | -0.60149875373298 | 0.000001405548 | 158 | -0.60144171081558 | 0.000003128248 |
| 159 | -0.60127926633045 | 0.00000456608 | 160 | -0.60103615097789 | 0.000005613821 |
| 161 | -0.60074937686649 | 0.00000618074 | 162 | -0.60046260275509 | 0.000006409107 |
| 163 | -0.60021948740253 | 0.00000617203 | 164 | -0.6000570429174 | 0.000006452761 |
| index | |||
|---|---|---|---|
| 1 | 0.4913985408708 | 0.32834200771458 | 0.000000000005 |
| 2 | 0.48039239059364 | 0.34424431884887 | 0.000000000009 |
| 3 | 0.46887182411212 | 0.35977800454415 | 0.00000000001 |
| 4 | 0.45684917793738 | 0.37492643094071 | 0.000000000011 |
| 5 | 0.44433732622008 | 0.38967337672414 | 0.000638704082 |
| 6 | 0.43134966696442 | 0.40400305049552 | 0.002774568368 |
| 7 | 0.41790010768125 | 0.41790010768125 | 0.002648678352 |
| 8 | 0.40400305049552 | 0.43134966696442 | 0.003134952159 |
| 9 | 0.38967337672414 | 0.44433732622008 | 0.003371109225 |
| 10 | 0.37492643094071 | 0.45684917793738 | 0.00362052744 |
| 11 | 0.35977800454415 | 0.46887182411212 | 0.003823085588 |
| 12 | 0.34424431884887 | 0.48039239059364 | 0.004004693717 |
| 13 | 0.32834200771458 | 0.4913985408708 | 0.004164215022 |
| 14 | 0.31208809973437 | 0.50187848928221 | 0.004306593404 |
| 15 | 0.2955 | 0.5118210136366 | 0.004434028868 |
| 16 | 0.27859547146416 | 0.52121546722988 | 0.004548494496 |
| 17 | 0.26139261591943 | 0.53005179024582 | 0.004651574501 |
| 18 | 0.2439098546144 | 0.53832052052841 | 0.004744445721 |
| 19 | 0.22616590852777 | 0.54601280371417 | 0.004828370754 |
| 20 | 0.20817977832145 | 0.55312040271358 | 0.004904191893 |
| 21 | 0.18997072399417 | 0.55963570653161 | 0.004972725611 |
| 22 | 0.17155824425739 | 0.56555173841774 | 0.005034518792 |
| 23 | 0.15296205565559 | 0.57086216333684 | 0.005090055986 |
| 24 | 0.13420207145331 | 0.5755612947529 | 0.005139889582 |
| 25 | 0.11529838031153 | 0.57964410071831 | 0.005184386706 |
| 26 | 0.0962712247762 | 0.58310620926216 | 0.005223998617 |
| 27 | 0.07714097960205 | 0.58594391307192 | 0.005258940541 |
| 28 | 0.05792812993477 | 0.58815417346327 | 0.005289495695 |
| 29 | 0.03865324937501 | 0.58973462363401 | 0.005315860418 |
| 30 | 0.01933697794767 | 0.59068357119853 | 0.005338252913 |
| 31 | 0 | 0.591 | 0.005356869923 |
| 32 | -0.01933697794767 | 0.59068357119853 | 0.005371839655 |
| 33 | -0.03865324937501 | 0.58973462363401 | 0.00538329912 |
| 34 | -0.05792812993477 | 0.58815417346327 | 0.005391294222 |
| 35 | -0.07714097960205 | 0.58594391307192 | 0.005395976833 |
| 36 | -0.0962712247762 | 0.58310620926216 | 0.005397361405 |
| 37 | -0.11529838031153 | 0.57964410071831 | 0.005395592218 |
| 38 | -0.13420207145331 | 0.5755612947529 | 0.005390634646 |
| 39 | -0.15296205565559 | 0.57086216333684 | 0.005382588982 |
| 40 | -0.17155824425739 | 0.56555173841774 | 0.005371424089 |
| 41 | -0.18997072399417 | 0.55963570653161 | 0.005357167758 |
| 42 | -0.20817977832145 | 0.55312040271358 | 0.005339817089 |
| 43 | -0.22616590852777 | 0.54601280371417 | 0.005319360695 |
| 44 | -0.2439098546144 | 0.53832052052841 | 0.005295824221 |
| 45 | -0.26139261591943 | 0.53005179024582 | 0.005269193571 |
| 46 | -0.27859547146416 | 0.52121546722988 | 0.005239457786 |
| 47 | -0.2955 | 0.5118210136366 | 0.005206556882 |
| 48 | -0.31208809973437 | 0.50187848928221 | 0.005170430831 |
| 49 | -0.32834200771458 | 0.4913985408708 | 0.005131018794 |
| 50 | -0.34424431884887 | 0.48039239059364 | 0.005088322391 |
| 51 | -0.35977800454415 | 0.46887182411212 | 0.00504230892 |
| 52 | -0.37492643094071 | 0.45684917793738 | 0.004992975694 |
| 53 | -0.38967337672414 | 0.44433732622008 | 0.004940222961 |
| 54 | -0.40400305049552 | 0.43134966696442 | 0.00488399491 |
| 55 | -0.41790010768125 | 0.41790010768125 | 0.004824218204 |
| 56 | -0.43134966696442 | 0.40400305049552 | 0.004760895309 |
| 57 | -0.44433732622008 | 0.38967337672414 | 0.004694049607 |
| 58 | -0.45684917793738 | 0.37492643094071 | 0.004623666088 |
| 59 | -0.46887182411212 | 0.35977800454415 | 0.004549682725 |
| 60 | -0.48039239059364 | 0.34424431884887 | 0.004472013635 |
| 61 | -0.4913985408708 | 0.32834200771459 | 0.004390610978 |
| 62 | -0.50187848928221 | 0.31208809973437 | 0.00430554631 |
| 63 | -0.5118210136366 | 0.2955 | 0.004216885068 |
| 64 | -0.52121546722988 | 0.27859547146416 | 0.004124710654 |
| 65 | -0.53005179024582 | 0.26139261591943 | 0.004028997465 |
| 66 | -0.53832052052841 | 0.2439098546144 | 0.003929757184 |
| 67 | -0.54601280371417 | 0.22616590852777 | 0.003827028338 |
| 68 | -0.55312040271358 | 0.20817977832145 | 0.003720966921 |
| 69 | -0.55963570653161 | 0.18997072399417 | 0.003611737022 |
| 70 | -0.56555173841774 | 0.17155824425739 | 0.00349933102 |
| 71 | -0.57086216333684 | 0.15296205565559 | 0.003383865867 |
| 72 | -0.5755612947529 | 0.13420207145331 | 0.003265638507 |
| 73 | -0.57964410071831 | 0.11529838031153 | 0.003143389946 |
| 74 | -0.58310620926216 | 0.0962712247762 | 0.003020584609 |
| 75 | -0.58594391307192 | 0.07714097960205 | 0.002890212871 |
| 76 | -0.58815417346327 | 0.05792812993477 | 0.002763390356 |
| 77 | -0.58973462363401 | 0.03865324937501 | 0.002615447991 |
| 78 | -0.59068357119853 | 0.01933697794767 | 0.002506482686 |
| 79 | -0.591 | 0 | 0.002042234839 |
| 80 | -0.59068357119853 | -0.01933697794767 | 0.002506482686 |
| 81 | -0.58973462363401 | -0.03865324937501 | 0.002615447991 |
| 82 | -0.58815417346327 | -0.05792812993477 | 0.002763390356 |
| 83 | -0.58594391307192 | -0.07714097960205 | 0.002890212871 |
| 84 | -0.58310620926216 | -0.0962712247762 | 0.003020584609 |
| 85 | -0.57964410071831 | -0.11529838031153 | 0.003143389946 |
| 86 | -0.5755612947529 | -0.13420207145331 | 0.003265638507 |
| 87 | -0.57086216333684 | -0.15296205565559 | 0.003383865867 |
| 88 | -0.56555173841774 | -0.17155824425739 | 0.00349933102 |
| 89 | -0.55963570653161 | -0.18997072399417 | 0.003611737022 |
| 90 | -0.55312040271358 | -0.20817977832145 | 0.003720966921 |
| 91 | -0.54601280371417 | -0.22616590852777 | 0.003827028338 |
| 92 | -0.53832052052841 | -0.2439098546144 | 0.003929757184 |
| 93 | -0.53005179024582 | -0.26139261591943 | 0.004028997465 |
| 94 | -0.52121546722988 | -0.27859547146416 | 0.004124710654 |
| 95 | -0.5118210136366 | -0.2955 | 0.004216885068 |
| 96 | -0.50187848928221 | -0.31208809973437 | 0.00430554631 |
| 97 | -0.4913985408708 | -0.32834200771459 | 0.004390610978 |
| 98 | -0.48039239059364 | -0.34424431884887 | 0.004472013635 |
| 99 | -0.46887182411212 | -0.35977800454415 | 0.004549682725 |
| 100 | -0.45684917793738 | -0.37492643094071 | 0.004623666088 |
| 101 | -0.44433732622008 | -0.38967337672414 | 0.004694049607 |
| 102 | -0.43134966696442 | -0.40400305049552 | 0.004760895309 |
| 103 | -0.41790010768125 | -0.41790010768125 | 0.004824218204 |
| 104 | -0.40400305049552 | -0.43134966696442 | 0.00488399491 |
| 105 | -0.38967337672414 | -0.44433732622008 | 0.004940222961 |
| 106 | -0.37492643094071 | -0.45684917793738 | 0.004992975694 |
| 107 | -0.35977800454415 | -0.46887182411212 | 0.00504230892 |
| 108 | -0.34424431884887 | -0.48039239059364 | 0.005088322391 |
| 109 | -0.32834200771458 | -0.4913985408708 | 0.005131018794 |
| 110 | -0.31208809973437 | -0.50187848928221 | 0.005170430831 |
| 111 | -0.2955 | -0.5118210136366 | 0.005206556882 |
| 112 | -0.27859547146416 | -0.52121546722988 | 0.005239457786 |
| 113 | -0.26139261591943 | -0.53005179024582 | 0.005269193571 |
| 114 | -0.2439098546144 | -0.53832052052841 | 0.005295824221 |
| 115 | -0.22616590852777 | -0.54601280371417 | 0.005319360695 |
| 116 | -0.20817977832145 | -0.55312040271358 | 0.005339817089 |
| 117 | -0.18997072399417 | -0.55963570653161 | 0.005357167758 |
| 118 | -0.17155824425739 | -0.56555173841774 | 0.005371424089 |
| 119 | -0.15296205565559 | -0.57086216333684 | 0.005382588982 |
| 120 | -0.13420207145331 | -0.5755612947529 | 0.005390634646 |
| 121 | -0.11529838031153 | -0.57964410071831 | 0.005395592218 |
| 122 | -0.0962712247762 | -0.58310620926216 | 0.005397361405 |
| 123 | -0.07714097960205 | -0.58594391307192 | 0.005395976833 |
| 124 | -0.05792812993477 | -0.58815417346327 | 0.005391294222 |
| 125 | -0.03865324937501 | -0.58973462363401 | 0.00538329912 |
| 126 | -0.01933697794767 | -0.59068357119853 | 0.005371839655 |
| 127 | 0 | -0.591 | 0.005356869923 |
| 128 | 0.01933697794767 | -0.59068357119853 | 0.005338252913 |
| 129 | 0.03865324937501 | -0.58973462363401 | 0.005315860418 |
| 130 | 0.05792812993477 | -0.58815417346327 | 0.005289495695 |
| 131 | 0.07714097960205 | -0.58594391307192 | 0.005258940541 |
| 132 | 0.0962712247762 | -0.58310620926216 | 0.005223998617 |
| 133 | 0.11529838031153 | -0.57964410071831 | 0.005184386706 |
| 134 | 0.13420207145331 | -0.5755612947529 | 0.005139889582 |
| 135 | 0.15296205565559 | -0.57086216333684 | 0.005090055986 |
| 136 | 0.17155824425739 | -0.56555173841774 | 0.005034518792 |
| 137 | 0.18997072399417 | -0.55963570653161 | 0.004972725611 |
| 138 | 0.20817977832145 | -0.55312040271358 | 0.004904191893 |
| 139 | 0.22616590852777 | -0.54601280371417 | 0.004828370754 |
| 140 | 0.2439098546144 | -0.53832052052841 | 0.004744445721 |
| 141 | 0.26139261591943 | -0.53005179024582 | 0.004651574501 |
| 142 | 0.27859547146416 | -0.52121546722988 | 0.004548494496 |
| 143 | 0.2955 | -0.5118210136366 | 0.004434028868 |
| 144 | 0.31208809973437 | -0.50187848928221 | 0.004306593404 |
| 145 | 0.32834200771458 | -0.4913985408708 | 0.004164215022 |
| 146 | 0.34424431884887 | -0.48039239059364 | 0.004004693717 |
| 147 | 0.35977800454415 | -0.46887182411212 | 0.003823085588 |
| 148 | 0.37492643094071 | -0.45684917793738 | 0.00362052744 |
| 149 | 0.38967337672414 | -0.44433732622008 | 0.003371109225 |
| 150 | 0.40400305049552 | -0.43134966696442 | 0.003134952159 |
| 151 | 0.41790010768125 | -0.41790010768125 | 0.002648678352 |
| 152 | 0.43134966696442 | -0.40400305049552 | 0.002774568368 |
| 153 | 0.44433732622008 | -0.38967337672414 | 0.000638704082 |
| 154 | 0.45684917793738 | -0.37492643094071 | 0.000000000011 |
| 155 | 0.46887182411212 | -0.35977800454415 | 0.00000000001 |
| 156 | 0.48039239059364 | -0.34424431884887 | 0.000000000009 |
| 157 | 0.4913985408708 | -0.32834200771458 | 0.000000000005 |
The interval and Poisson weights sum to masses , , and as stated in Lemma 4.2.
Appendix E Dyadic subdivisions
The supports are , , and
(by conjugation symmetry the
upper half suffices). On each support , the leaves are ordered from left to right. Their
depths are listed in run-length form: an entry
means that depth occurs on consecutive leaves. Set
and . The printed sequence
satisfies for each support. On a real
support the th interval is
. On it is
for . On each leaf, the Arb upper bound for
is strictly below its cap in Table B.1, and
that table keeps the worst leaf for each support. The full leafwise Arb
upper bounds are in anc/
| support | block | depth:repeat |
|---|---|---|
| 1 |
5:1, |
|
| 2 |
10:18, |
|
| 3 |
11:4, |
|
| 4 |
10:28, |
|
| 5 |
11:2, |
|
| 6 |
10:32, |
|
| 7 |
11:2, |
|
| 8 |
10:29, |
|
| 9 |
11:6, |
|
| 10 |
10:15, |
|
| 11 |
11:12, |
|
| 12 |
12:4, |
|
| 13 |
11:4, |
|
| 14 |
14:22, |
|
| 1 |
8:1, |
|
| 2 |
11:11, |
|
| 3 |
10:12, |
|
| 4 |
11:4, |
|
| 5 |
10:27, |
|
| 6 |
11:2, |
|
| 7 |
10:66, |
|
| 8 |
11:2, |
|
| 9 |
10:28, |
|
| 10 |
11:6, |
|
| 11 |
10:12, |
|
| 12 |
11:26, |
|
| 13 |
12:10, |
|
| 14 |
11:1, |
|
| 15 |
14:1, |
|
| 1 |
14:4, |
|
| 2 |
11:6, |
|
| 3 |
10:12, |
|
| 4 |
9:4, |
|
| 5 |
10:8, |
|
| 6 |
9:14, |
|
| 7 |
10:2, |
|
| 8 |
9:16, |
|
| 1 | 2:4 | |
| 1 |
3:1, |
|
| 2 |
11:30, |
|
| 3 |
10:8, |
|
| 4 |
9:1, |
|
| 5 |
10:8, |
|
| 6 |
9:2, |
|
| 7 |
10:6, |
|
| 8 |
9:3, |
|
| 9 |
10:2, |
Appendix F Computer checks
Lemma 4.2 is proved by the interval computation of
check_
| script | statements checked | time |
|---|---|---|
|
check_ |
(2.5) and Table 2.1; (2.3) for and the four determinant evaluations in Lemma 2.2 for small sizes. | |
|
check_ |
the cut points and every entry of Table A.1; (3.8), , and ; in Lemma 3.4; the potentials of Lemma 3.3 for . | |
|
check_ |
Lemma 4.2: Tables B.1, B.2, D.1 and D.2, (B.1), (B.2), (4.2); the constants of Lemma 4.4. | |
|
check_ |
(5.2), (5.1) and Table 5.1. |
Statements and declarations
Competing interests. The author has no competing interests.
Funding. No funding was received for this work.
Data availability. The scripts of Appendix F, the data of the measure and the outputs of the scripts are included in the anc/ attachment accompanying this manuscript.
References
- [1] F. Calegari, V. Dimitrov, and Y. Tang, The linear independence of , , and , preprint (2024), arXiv:2408.15403v2.
- [2] NIST Digital Library of Mathematical Functions, https://dlmf.nist.gov/, Release 1.2.8 of 2026-09-15, F. W. J. Olver et al., eds.
- [3] M. Hata, Rational approximations to the dilogarithm, Trans. Amer. Math. Soc. 336 (1993), no. 1, 363–387, https://doi.org/10.1090/S0002-9947-1993-1147401-5. MR1147401
- [4] C. Krattenthaler, Advanced determinant calculus, Séminaire Lotharingien de Combinatoire 42 (1999), Article B42q, 67 pp., arXiv:math/9902004.
- [5] F. Johansson, Arb: efficient arbitrary-precision midpoint-radius interval arithmetic, IEEE Trans. Comput. 66 (2017), no. 8, 1281–1292, https://doi.org/10.1109/TC.2017.2690633.
- [6] T. Prellberg, Three irrationality results for the dilogarithm: Rhin–Viola and Viola–Zudilin constructions at , , and , preprint (2026), arXiv:2609.06895v1.
- [7] G. Rhin and C. Viola, The permutation group method for the dilogarithm, Ann. Sc. Norm. Super. Pisa Cl. Sci. (5) 4 (2005), no. 3, 389–437, https://doi.org/10.2422/2036-2145.2005.3.02. MR2185863
- [8] G. Rhin and C. Viola, Linear independence of , and , Mosc. J. Comb. Number Theory 8 (2019), no. 1, 81–96, https://doi.org/10.2140/moscow.2019.8.81. MR3864310
- [9] E. B. Saff and V. Totik, Logarithmic Potentials with External Fields, Grundlehren der Mathematischen Wissenschaften, vol. 316, 1st ed., Springer, 1997, https://doi.org/10.1007/978-3-662-03329-6.
- [10] C. Viola and W. Zudilin, Linear independence of dilogarithmic values, J. Reine Angew. Math. 736 (2018), 193–223, https://doi.org/10.1515/crelle-2015-0030; preprint version: Max-Planck-Institut für Mathematik Preprint Series 2014 (26), https://archive.mpim-bonn.mpg.de/id/eprint/1914/. MR3769989