Papers
Topics
Authors
Recent
Search
2000 character limit reached

General-Skewness Formalism

Updated 9 July 2026
  • General-skewness formalism is a family of approaches that extends classical skewness by using quantile functionals, Fréchet means, and tail comparisons to capture asymmetry.
  • It incorporates quantile-averaged measures, non-local Bayesian priors, and skewness matrices to address challenges in heavy-tailed distributions and multidimensional data.
  • The framework is applied across statistics, stochastic processes, cosmology, and turbulence, providing tailored observable extraction and improved analytical precision.

to=arxiv_search.search 亚历山大发json {"query":"all:(Arachchige et al., 2019) OR all:(Shaw et al., 2009) OR all:(Giacalone et al., 2016) OR all:(Rinaldi, 2017) OR all:(Yamauchi et al., 2022) OR all:(Bentkus et al., 2011) OR all:(Li, 2018) OR all:(Chu et al., 25 Aug 2025) OR all:(Roskill et al., 27 Nov 2025)","max_results":10,"sort_by":"submittedDate","sort_order":"descending"}【อ่านข้อความเต็มjson to=arxiv_search.search  ̄色 {"results":[{"arxiv_id":"(Roskill et al., 27 Nov 2025)","version":"v1","idv":"(Roskill et al., 27 Nov 2025)v1","title":"Skew-spectra: a generalization to spin-ss","authors":"Aidan Roskill, Solène Maleubre, David Alonso, Pedro G. Ferreira","categories":"astro-ph.CO","published":"2025-11-27","updated":"2025-11-27","pdf_url":"http://arxiv.org/pdf/([2511.22596](/papers/2511.22596))v1","abs_url":"https://arxiv.org/abs/([2511.22596](/papers/2511.22596))v1"},{"arxiv_id":"([2508.17998](/papers/2508.17998))","version":"v1","idv":"([2508.17998](/papers/2508.17998))v1","title":"Generalized Parton Distributions from Lattice QCD with Asymmetric Momentum Transfer: Unpolarized Quarks at Nonzero Skewness","authors":"M. Constantinou, M. Cè, A. Hackl, M. V. Polyakov, K. Ottnad, S. Vitale","categories":"hep-lat hep-ph","published":"2025-08-25","updated":"2025-08-25","pdf_url":"http://arxiv.org/pdf/([2508.17998](/papers/2508.17998))v1","abs_url":"https://arxiv.org/abs/([2508.17998](/papers/2508.17998))v1"},{"arxiv_id":"([1608.01823](/papers/1608.01823))","version":"v1","idv":"([1608.01823](/papers/1608.01823))v1","title":"Skewness of elliptic flow fluctuations","authors":"Jean-Yves Ollitrault, Lie-Wen Chen, Ante Bilandzic, Jiangyong Jia, Frédérique Gardim","categories":"nucl-th","published":"2016-08-05","updated":"2016-08-05","pdf_url":"http://arxiv.org/pdf/([1608.01823](/papers/1608.01823))v1","abs_url":"https://arxiv.org/abs/([1608.01823](/papers/1608.01823))v1"},{"arxiv_id":"([1812.08415](/papers/1812.08415))","version":"v3","idv":"([1812.08415](/papers/1812.08415))v3","title":"On general skew Brownian motions","authors":"Liping Li, Christophe Profeta, Lin Wu, Xiaowen Zhou","categories":"math.PR","published":"2018-12-20","updated":"2021-01-24","pdf_url":"http://arxiv.org/pdf/([1812.08415](/papers/1812.08415))v3","abs_url":"https://arxiv.org/abs/([1812.08415](/papers/1812.08415))v3"},{"arxiv_id":"([1912.06996](/papers/1912.06996))","version":"v3","idv":"([1912.06996](/papers/1912.06996))v3","title":"Mean skewness measures","authors":"Tom Verity, Jo Hardin, Paul D. McNicholas","categories":"stat.ME","published":"2019-12-15","updated":"2021-11-12","pdf_url":"http://arxiv.org/pdf/([1912.06996](/papers/1912.06996))v3","abs_url":"https://arxiv.org/abs/([1912.06996](/papers/1912.06996))v3"},{"arxiv_id":"([1111.6358](/papers/1111.6358))","version":"v2","idv":"([1111.6358](/papers/1111.6358))v2","title":"Bounds for tail probabilities of martingales using skewness and kurtosis","authors":"Vidmantas Bentkus, Jurgita Juškevičius","categories":"math.PR math.ST","published":"2011-11-28","updated":"2013-01-11","pdf_url":"http://arxiv.org/pdf/([1111.6358](/papers/1111.6358))v2","abs_url":"https://arxiv.org/abs/([1111.6358](/papers/1111.6358))v2"},{"arxiv_id":"([0901.0434](/papers/0901.0434))","version":"v1","idv":"([0901.0434](/papers/0901.0434))v1","title":"The alchemy of probability distributions: beyond Gram-Charlier expansions, and a skew-kurtotic-normal distribution from a rank transmutation map","authors":"W. T. Shaw, I. R. C. Buckley","categories":"q-fin.CP math.ST","published":"2009-01-05","updated":"2009-01-05","pdf_url":"http://arxiv.org/pdf/([0901.0434](/papers/0901.0434))v1","abs_url":"https://arxiv.org/abs/([0901.0434](/papers/0901.0434))v1"}]} to=arxiv_search.search 银航json {"query":"all:(Yamauchi et al., 2022) OR all:(Ding et al., 2020) OR all:(Oya et al., 2021) OR all:(Gallaugher et al., 2017) OR all:(Karlsson et al., 2021) OR all:(Kovchegov, 2020) OR all:(Fujimoto et al., 1 Feb 2026) OR all:(Rubio, 9 Mar 2026) OR all:(Mendonça, 22 Jun 2026)","max_results":20,"sort_by":"submittedDate","sort_order":"descending"}【อ่านข้อความเต็มjson to=arxiv_search.search সেট {"results":[{"arxiv_id":"(Mendonça, 22 Jun 2026)","version":"v1","idv":"(Mendonça, 22 Jun 2026)v1","title":"Skewness tunes the small-drift record rate of random walks and Lévy flights","authors":"A. N. M. Vigolo, L. F. Cugliandolo, M. Delorme, E. Bertin","categories":"cond-mat.stat-mech math.PR","published":"2026-06-22","updated":"2026-06-22","pdf_url":"http://arxiv.org/pdf/([2606.23553](/papers/2606.23553))v1","abs_url":"https://arxiv.org/abs/([2606.23553](/papers/2606.23553))v1"},{"arxiv_id":"([2603.08285](/papers/2603.08285))","version":"v1","idv":"([2603.08285](/papers/2603.08285))v1","title":"An objective non-local prior for skew-symmetric models","authors":"Javier F. Codoñer, Víctor Elvira, Francisco J. Rubio","categories":"stat.ME","published":"2026-03-09","updated":"2026-03-09","pdf_url":"http://arxiv.org/pdf/([2603.08285](/papers/2603.08285))v1","abs_url":"https://arxiv.org/abs/([2603.08285](/papers/2603.08285))v1"},{"arxiv_id":"([2602.01108](/papers/2602.01108))","version":"v1","idv":"([2602.01108](/papers/2602.01108))v1","title":"Skewness in the Hellings-Downs curve","authors":"Joseph M. A. Allen, Hyung Do Kim, Chiara Caprini, Christopher T. Byrnes","categories":"gr-qc astro-ph.CO hep-ph","published":"2026-02-01","updated":"2026-02-01","pdf_url":"http://arxiv.org/pdf/([2602.01108](/papers/2602.01108))v1","abs_url":"https://arxiv.org/abs/([2602.01108](/papers/2602.01108))v1"},{"arxiv_id":"([2211.13453](/papers/2211.13453))","version":"v2","idv":"([2211.13453](/papers/2211.13453))v2","title":"Skewness consistency relation in large-scale structure and test of gravity theory","authors":"Daisuke Yamauchi, Takahiro Terada, Atsushi Taruya, Tomo Takahashi, Kazuya Koyama","categories":"astro-ph.CO gr-qc hep-ph","published":"2022-11-24","updated":"2023-03-28","pdf_url":"http://arxiv.org/pdf/([2211.13453](/papers/2211.13453))v2","abs_url":"https://arxiv.org/abs/([2211.13453](/papers/2211.13453))v2"},{"arxiv_id":"([2108.04019](/papers/2108.04019))","version":"v1","idv":"([2108.04019](/papers/2108.04019))v1","title":"Identification in Bayesian Estimation of the Skewness Matrix in a Multivariate Skew-Elliptical Distribution","authors":"Naoyuki Yoshida, Hiroshi Yamada, Teppei Watanabe","categories":"q-fin.ST stat.ME","published":"2021-08-09","updated":"2021-08-09","pdf_url":"http://arxiv.org/pdf/([2108.04019](/papers/2108.04019))v1","abs_url":"https://arxiv.org/abs/([2108.04019](/papers/2108.04019))v1"},{"arxiv_id":"([2105.11182](/papers/2105.11182))","version":"v3","idv":"([2105.11182](/papers/2105.11182))v3","title":"Vector autoregression models with skewness and heavy tails","authors":"Florian Huber, Michael Pfarrhofer, Todd E. Clark","categories":"econ.EM","published":"2021-05-24","updated":"2021-07-14","pdf_url":"http://arxiv.org/pdf/([2105.11182](/papers/2105.11182))v3","abs_url":"https://arxiv.org/abs/([2105.11182](/papers/2105.11182))v3"},{"arxiv_id":"([2009.10305](/papers/2009.10305))","version":"v4","idv":"([2009.10305](/papers/2009.10305))v4","title":"A new life of Pearson's skewness","authors":"Iddo Ben-Ari, Ross G. Pinsky, Pedro G. Ramos","categories":"math.PR","published":"2020-09-22","updated":"2022-04-13","pdf_url":"http://arxiv.org/pdf/([2009.10305](/papers/2009.10305))v4","abs_url":"https://arxiv.org/abs/([2009.10305](/papers/2009.10305))v4"},{"arxiv_id":"([2008.10717](/papers/2008.10717))","version":"v2","idv":"([2008.10717](/papers/2008.10717))v2","title":"Enhanced diffusivity and skewness of a diffusing tracer in the presence of an oscillating wall","authors":"Jiaqi Wang, Kranthi K. Mandadapu, Shane D. Ross","categories":"physics.flu-dyn","published":"2020-08-24","updated":"2021-03-12","pdf_url":"http://arxiv.org/pdf/([2008.10717](/papers/2008.10717))v2","abs_url":"https://arxiv.org/abs/([2008.10717](/papers/2008.10717))v2"},{"arxiv_id":"([1704.02531](/papers/1704.02531))","version":"v1","idv":"([1704.02531](/papers/1704.02531))v1","title":"Three Skewed Matrix Variate Distributions","authors":"Paul D. McNicholas, Sara K. Murray, Brendan Murphy, Isobel C. Gormley","categories":"stat.ME","published":"2017-04-08","updated":"2017-04-08","pdf_url":"http://arxiv.org/pdf/([1704.02531](/papers/1704.02531))v1","abs_url":"https://arxiv.org/abs/([1704.02531](/papers/1704.02531))v1"}]} to=arxiv_search.search 天天爱彩票网站json {"query":"all:(Rinaldi, 2017) OR title:\"non-zero skewness\" ADS/QCD","max_results":10,"sort_by":"submittedDate","sort_order":"descending"}【อ่านข้อความเต็มjson to=arxiv_search.search _天天 {"results":[{"arxiv_id":"(Rinaldi, 2017)","version":"v1","idv":"(Rinaldi, 2017)v1","title":"GPDs at non-zero skewness in ADS/QCD model","authors":"M. Traini, S. Zambello, V. Vento, A. Courtoy","categories":"hep-ph","published":"2017-03-01","updated":"2017-03-01","pdf_url":"http://arxiv.org/pdf/([1703.00348](/papers/1703.00348))v1","abs_url":"https://arxiv.org/abs/([1703.00348](/papers/1703.00348))v1"}]} to=arxiv_search.search 菲龙json {"query":"all:(Michele et al., 20 Jun 2025) OR all:(Bos et al., 2011)","max_results":10,"sort_by":"submittedDate","sort_order":"descending"}【อ่านข้อความเต็มjson to=arxiv_search.search 北京赛车怎么 {"results":[{"arxiv_id":"(Michele et al., 20 Jun 2025)","version":"v1","idv":"(Michele et al., 20 Jun 2025)v1","title":"Skewness-Kurtosis: small samples and power-law behavior","authors":"C. Tsallis, M. Gell-Mann, Y. Y. Yordanov, M. G. E. da Luz, C. Anteneodo, M. S. Ribeiro","categories":"physics.data-an physics.soc-ph","published":"2025-06-20","updated":"2025-06-20","pdf_url":"http://arxiv.org/pdf/([2506.16906](/papers/2506.16906))v1","abs_url":"https://arxiv.org/abs/([2506.16906](/papers/2506.16906))v1"},{"arxiv_id":"([1101.4726](/papers/1101.4726))","version":"v1","idv":"([1101.4726](/papers/1101.4726))v1","title":"Reynolds number effect on the velocity increment skewness in isotropic turbulence","authors":"B. Castaing, Y. Gagne, E.J. Hopfinger, C. Meneveau, F. Daviaud","categories":"physics.flu-dyn physics.ao-ph","published":"2011-01-25","updated":"2011-01-25","pdf_url":"http://arxiv.org/pdf/([1101.4726](/papers/1101.4726))v1","abs_url":"https://arxiv.org/abs/([1101.4726](/papers/1101.4726))v1"}]} Across the cited literature, the expression general-skewness formalism denotes a family of non-equivalent frameworks for representing, estimating, or exploiting asymmetry. In statistical methodology, it extends skewness beyond the standardized third central moment by using quantiles, Fréchet means, stochastic dominance, variance-mean mixtures, or discrepancy-based priors. In stochastic-process theory, it appears as local-time drift measures and as asymmetry parameters controlling record statistics. In cosmology, heavy-ion physics, and field theory, it denotes higher-order observables that compress bispectrum information, split higher-order cumulants, or parametrize longitudinal momentum asymmetry at nonzero skewness. The common theme is not a single canonical definition, but a shift from a single summary coefficient to a structured formalism tailored to the object under study (Arachchige et al., 2019, Kovchegov, 2020, Li, 2018, Roskill et al., 27 Nov 2025, Chu et al., 25 Aug 2025).

1. Classical skewness and the need for generalization

Classical skewness is often identified with Pearson’s moment coefficient

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},

together with Pearson’s first and second skewness coefficients,

Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.

The difficulty emphasized in the literature is that these criteria can disagree, can be ill-defined when moments are infinite, and can fail to provide a unified notion of the sign of asymmetry (Kovchegov, 2020).

One response is to replace isolated summary locations by a continuum of Fréchet means. For p1p \ge 1, the Fréchet pp-mean is

νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].

The paper on a new life of Pearson’s skewness defines truly positively skewed distributions as those for which νp\nu_p is strictly increasing in pp, and truly negatively skewed distributions by the reverse monotonicity. In this framework, ν1\nu_1 is the median, ν2\nu_2 is the mean, and for unimodal distributions γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},0 can be interpreted as the mode; moreover, γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},1 iff γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},2 (Kovchegov, 2020).

This formalism is coupled to a tail-comparison principle. After cutting at γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},3, reflecting the left tail, and weighting both sides by γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},4, strict stochastic dominance of the scaled right tail over the scaled left tail implies that γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},5 increases with γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},6. The same paper states the derivative criterion

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},7

so the sign of γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},8 is governed by a weighted right-versus-left tail comparison (Kovchegov, 2020).

A related but distinct generalization appears in the joint study of skewness and kurtosis. For a sample γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},9,

Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.0

The paper on small samples and power-law behavior emphasizes that admissible Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.1 pairs are constrained by inequalities such as

Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.2

and that the lower boundary for small Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.3 is empirically described by a parabola Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.4 for Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.5 (Michele et al., 20 Jun 2025). This suggests that generalized skewness analysis often requires a joint geometry of higher moments rather than an isolated skewness coefficient.

2. Quantile-averaged and integral skewness measures

A second major line of development replaces moment-based asymmetry by quantile-based functionals. The mean-skewness framework begins from quantile-based skewness coefficients that generalize Bowley’s coefficient for Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.6, then averages them over the full interval instead of fixing Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.7. The objective stated in the paper is to “average the skewness measures over all Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.8” and “provide interval estimators for the new measure with good coverage properties” (Arachchige et al., 2019).

The key quantities are the integrated coefficients

Skew1=μmodeσ,Skew2=3μmedianσ.\text{Skew}_1=\frac{\mu-\text{mode}}{\sigma}, \qquad \text{Skew}_2=3\frac{\mu-\text{median}}{\sigma}.9

together with weighted forms such as

p1p \ge 10

The paper defines the mean skewness as one half the AUC and emphasizes that the weighted version downweights extreme quantiles, “where estimation is less stable” (Arachchige et al., 2019).

Estimation proceeds by discretizing the integral on a grid

p1p \ge 11

and using

p1p \ge 12

with similar formulas for p1p \ge 13 and the weighted forms. The paper reports that p1p \ge 14 performed well in simulations; asymptotic variances and covariances are derived using the Delta method and standard quantile variance approximations; kernel estimators are used for the quantile densities involved; and the resulting confidence intervals had “excellent coverage properties” and were “more stable and representative than intervals based on a fixed, arbitrarily chosen p1p \ge 15” (Arachchige et al., 2019).

The comparison with earlier work is explicit. Bowley’s original coefficient is recovered by setting p1p \ge 16, while Groeneveld & Meeden (1984) integrated numerator and denominator separately; the mean-skewness paper instead integrates the ratio directly and thereby eliminates the need to select a particular p1p \ge 17 (Arachchige et al., 2019). A common misconception is that quantile-based skewness is necessarily tied to quartiles; this literature shows that quartiles are only one point in a continuum.

3. Parametric skewness, skewness matrices, and Bayesian regularization

Another use of general-skewness formalisms is to build skewness directly into parametric families. A foundational construction is the rank transmutation map

p1p \ge 18

which composes the CDF of one distribution with the inverse CDF of another. The quadratic rank transmutation map

p1p \ge 19

induces

pp0

The paper contrasts this exact construction with Gram-Charlier and Edgeworth–Cornish-Fisher expansions, which can yield negative densities and require finite higher moments (Shaw et al., 2009).

Variance-mean mixtures provide a matrix-valued generalization. In the matrix variate setting,

pp1

where pp2 is the skewness matrix, pp3, and different choices of the mixing variable pp4 produce matrix variate generalized hyperbolic, variance-gamma, and normal inverse Gaussian families. The same paper states that vectorization yields the usual multivariate analogues, with pp5 entering both the linear mean adjustment and the quadratic form pp6 (Gallaugher et al., 2017).

In multivariate skew-elliptical models, the skewness parameter becomes a full matrix pp7: pp8 Here diagonal entries correspond to marginal skewness and off-diagonal entries encode co-skewness. The difficulty identified by Harvey et al. (2010) and revisited later is label switching in Gibbs sampling. The proposed solution is a positive lower-triangular constraint

pp9

combined, in the sparse version, with horseshoe priors (Oya et al., 2021). This turns skewness estimation into an identification problem as much as a shape problem.

A parallel Bayesian line appears in skew-symmetric models with density

νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].0

The proposed objective non-local prior is built from a discrepancy measure νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].1 and a signed discrepancy νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].2, then induces the MOOMIN prior

νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].3

The paper states that this prior is non-local, symmetric about zero, assigns zero prior density at νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].4, and avoids user-specified hyperparameters; in the skew-normal case, it is well approximated by

νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].5

with νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].6, νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].7, and νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].8 (Rubio, 9 Mar 2026).

Macroeconomic VAR models provide a further operational example. There, generalized hyperbolic skew Student’s νp=argminaRE[Xap].\nu_p=\mathop{\mathrm{argmin}}_{a\in\mathbb{R}} E[|X-a|^p].9 errors are introduced through a normal variance-mean mixture with inverse-gamma latent scales,

νp\nu_p0

or, in the reduced-form version,

νp\nu_p1

In this setting, νp\nu_p2 is the skewness parameter vector and νp\nu_p3 control tail thickness (Karlsson et al., 2021).

4. Stochastic-process and probability-inequality formalisms

In probability theory, generalized skewness often enters through sharp inequalities or singular drift terms. Bentkus and Juškevičius derive tail bounds for martingales with bounded increments by replacing Hoeffding’s variance proxy with explicit functions of skewness and kurtosis: νp\nu_p4 These define effective variances through averages of νp\nu_p5 or νp\nu_p6, and the resulting tail bound has the form

νp\nu_p7

Their Theorem 1.4 unifies variance, skewness, and kurtosis information by using the minimum among the available bounds for each increment (Bentkus et al., 2011).

A more structural use of skewness appears in general skew Brownian motion. Starting from the Dirichlet form

νp\nu_p8

on νp\nu_p9, the associated diffusion can be represented, when it is a semimartingale, as a weak solution of

pp0

The paper develops an irreducible decomposition into effective intervals, classifies real barriers and pseudo barriers, and identifies the skewness measure through

pp1

Existence and uniqueness are therefore controlled by the measure pp2, not by a single scalar skewness parameter (Li, 2018).

Random-walk record statistics provide yet another asymmetry formalism. For small positive drift pp3, if centered steps are attracted to a stable law with index pp4, positivity parameter pp5, and pp6, then

pp7

The paper emphasizes that the exponent is set by the asymmetry only through pp8, and derives the result from a Mellin transform of the harmonic sum in the Spitzer-Baxter identity (Mendonça, 22 Jun 2026). This is a different use of “skewness”: asymmetry is encoded in the positivity parameter of the limiting stable law and controls the small-drift record-rate exponent.

5. Higher-order observables in nuclear physics, cosmology, and hadron structure

In heavy-ion physics, skewness is used to resolve non-Gaussian flow fluctuations. For elliptic flow pp9, the reaction-plane quantities are

ν1\nu_10

The key result is that the splitting between higher-order cumulants is governed by skewness: ν1\nu_11 with the experimental estimator

ν1\nu_12

The skewness is negative and arises from the upper bound on the initial eccentricity (Giacalone et al., 2016).

In large-scale structure, skewness parameters are connected directly to second-order perturbation theory. The real-space parameters ν1\nu_13 are connected to the bispectrum and to the kernel

ν1\nu_14

The observable combination

ν1\nu_15

is the real-space skewness consistency relation, and redshift-space analogues determine ν1\nu_16, ν1\nu_17, and ν1\nu_18 (Yamauchi et al., 2022).

A compression of three-point information appears in skew-spectra. For spin-ν1\nu_19 fields on the sphere, the skew-spectrum is the cross-power spectrum of a quadratic map with an original field,

ν2\nu_20

where the product field is expanded with spin-weighted spherical harmonics and Wigner-ν2\nu_21 symbols. The formalism is presented as the first extension of skew-spectra to arbitrary spin-ν2\nu_22 fields and is applied to weak lensing and CMB polarization (Roskill et al., 27 Nov 2025).

For pulsar timing arrays, the third central moment of the Hellings-Downs correlation yields a non-Gaussian observable that remains finite in the large-source-number limit. The paper defines the cosmic skewness through a three-point averaged correlation function,

ν2\nu_23

and gives

ν2\nu_24

This extends Allen’s variance calculation to third order (Fujimoto et al., 1 Feb 2026).

A terminological distinction is essential in hadron structure. In generalized parton distributions, the skewness parameter ν2\nu_25 is the longitudinal momentum asymmetry between initial and final nucleon states, not a third central moment. In the AdS/QCD non-forward formalism, nonzero skewness requires two-body light-front wave functions and shifted variables ν2\nu_26 built from

ν2\nu_27

with analogous expressions for spectators (Rinaldi, 2017). In lattice QCD, the asymmetric-frame general-skewness formalism parametrizes nonlocal matrix elements by Lorentz-invariant amplitudes ν2\nu_28, from which one reconstructs

ν2\nu_29

The paper also notes a special case with only longitudinal transfer, where only an admixture of γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},00 and γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},01 is directly accessible (Chu et al., 25 Aug 2025).

6. Transport, turbulence, and finite-sample asymmetry

In advection-diffusion problems, skewness can be treated through the full moment hierarchy rather than through static distributional summaries. For a passive tracer with concentration γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},02, the Aris moments

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},03

satisfy

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},04

and the longitudinal skewness is

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},05

Using an inverse Helmholtz operator, the paper derives compact series for variance and third moments, shows that skewness is exactly zero for linear shear flows at all times, and shows that for the nonlinear Stokes layer the sign can be controlled through the oscillating phase; for single-frequency wall motion, long-time skewness decays as γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},06, faster than the steady-flow γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},07 case (Ding et al., 2020).

In isotropic turbulence, skewness is formulated through the second- and third-order longitudinal structure functions,

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},08

The EDQNM model and the multifractal formalism both produce power-law corrections to inertial-range skewness at experimentally accessible Reynolds numbers, but with different interpretations: in EDQNM the correction is a finite Reynolds number effect, while in the multifractal formalism it is an intermittency correction that persists at arbitrarily high Reynolds number (Bos et al., 2011).

Finally, the small-sample skewness-kurtosis literature adds a cautionary boundary condition to all generalized-skewness formalisms. The relation

γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},09

explains when the empirical γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},10 law γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},11 can emerge. The paper states that this occurs predominantly in heavy-tailed distributions and medium or large sample sizes, and does not hold for γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},12 to γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},13 because of strong algebraic constraints on admissible γ=E[(Xμ)3]σ3,\gamma = \frac{E\left[(X-\mu)^3\right]}{\sigma^3},14 values (Michele et al., 20 Jun 2025).

Taken together, these developments show that “general-skewness formalism” is best understood as a methodological pattern: skewness is promoted from a single descriptive coefficient to an operator, a family of quantile functionals, a matrix parameter, a local-time measure, a perturbative consistency relation, or a compressed higher-order observable. A plausible implication is that asymmetry is most informative when embedded in the native structure of the problem—quantiles for robust distributional shape, amplitudes for non-forward hadron structure, cumulants for flow fluctuations, kernels for large-scale structure, and drift or local time for stochastic processes.

Definition Search Book Streamline Icon: https://streamlinehq.com
References (19)

Topic to Video (Beta)

No one has generated a video about this topic yet.

Whiteboard

No one has generated a whiteboard explanation for this topic yet.

Follow Topic

Get notified by email when new papers are published related to General-Skewness Formalism.