Pith. sign in

REVIEW 3 major objections 5 minor 1 cited by

Universality of the least singular value for the sum of random matrices

T0 review · 3 major / 5 minor · reviewed 2026-08-14 · deepseek-v4-flash

Pith's one-line read For sums of two Haar-conjugated diagonal matrices, the smallest singular value has the same limiting distribution as for a Gaussian matrix.

desk verdict A new and likely correct least-singular-value universality theorem, but the proof leans on a sketched, corrected comparison (Prop 7.5) that should be the referee's focus. read the letter →

arxiv 1908.04060 v2 pith:PXDI3KZX submitted 2019-08-12 math.PR

classification math.PR MSC 60B2015B5246L54
keywords leastsingularvalueuniversalitysumofrandommatricesHaarunitaryfreeconvolutionBrownianmotionflowlocallawhardedge
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper proves that the smallest singular value of the random matrix sum $M = R^* X T + U^* Y V$, where $R,T,U,V$ are independent Haar-distributed unitary matrices and $X,Y$ are deterministic diagonal matrices, has the same limiting distribution as the smallest singular value of a matrix of i.i.d. complex Gaussian entries. Concretely, for every $r \ge 0$, $\mathbb{P}(N \lambda_1(M) \le r) = 1 - e^{-r^2} + O(N^{-c})$ with an absolute constant $c>0$ uniform in $r$. The interest is that $M$ is strongly correlated, with no independent entries, so universality of the least singular value is extended from entrywise-independent models to a natural unitary-invariant sum model. The paper also shows the real orthogonal version is genuinely different, with limiting law $1 - e^{-r^2/2 - r}$ and a hard edge at zero.

What carries the argument

The load-bearing object is the $2N\times 2N$ Hermitian symmetrization of the matrix $\widehat M(t)$, whose $2N$ eigenvalues are the singular values of $\widehat M(t)$ and their negatives. The paper feeds this matrix into a specially chosen unitary Brownian flow (equations (3.2)–(3.5)) so that the eigenvalue flow is an SDE of the form $d\lambda_i = (2N)^{-1/2}dB_i + (2N)^{-1}\sum_{j\ne i}(1-\gamma_{ij})(\lambda_i-\lambda_j)^{-1}dt + R_i$, a symmetrized Brownian motion flow with a remainder controlled by eigenvector delocalization. The second pillar is the system (4.51) of Stieltjes-transform equations whose solution is the free convolution $\mu_X^{\mathrm{sym}}\boxplus\mu_Y^{\mathrm{sym}}$; a stability analysis of this system (Propositions 4.10–4.11) yields the local law for the Green's function and the eigenvector estimates that bound the $\gamma_{ij}$ and $R_i$. Short-time universality for the symmetrized flow (Proposition 7.5, with a missing regularity hypothesis supplied) then couples the singular values to those of a Gaussian matrix, and the explicit Gaussian law finishes the proof.

What would settle it

Take a concrete pair of deterministic spectra satisfying assumptions (1)–(6) but for which the free-convolution density at zero vanishes; if the edge mechanism claimed here is right, $N\lambda_1$ should develop a hard edge or a different edge scale instead of the soft-edge law $1-e^{-r^2}$. For spectra that do satisfy assumption (7), compute the empirical CDF of $N\lambda_1$ at a fixed $r$ for increasing $N$ and check that the discrepancy from $1-e^{-r^2}$ decays like a power of $N$.

Watch

Extended reading notes

Core claim

The central claim is that universality of the least singular value holds for the ensemble $M = R^*XT + U^*YV$, with deterministic diagonal $X,Y$ satisfying assumptions (1)–(7) on their empirical measures. In this regime the rescaled least singular value $N\lambda_1(M)$ converges in distribution to the complex Gaussian law, and the convergence is quantitative: the maximum error over all $r\ge 0$ is $O(N^{-c})$. The paper identifies the normalization $\rho(0)=1/\pi$ in assumption (7), where $\rho$ is the density of the free convolution of the two limiting symmetrized spectra, as the condition that places the edge of the spectrum at exactly the Gaussian scale; without it the constant in the limiting law would change. The proof is dynamical: a unitary Brownian flow preserving the law of $M$ is shown to drive the singular values by a symmetrized Brownian-type eigenvalue flow, and short-time relaxation to the Gaussian process yields the theorem.

Load-bearing premise

The whole proof rests on the assumption that the deterministic limiting spectrum of the sum has, near its edge at zero, a density that is bounded away from zero and normalized to exactly $1/\pi$ at zero; the authors state this condition is difficult to verify in general and supply only partial sufficient conditions.

Editorial extensions

If this is right

  • For every $r\ge 0$, the probability that $N\lambda_1(M)\le r$ is $1-e^{-r^2}+O(N^{-c})$, so the least singular value is $O(1/N)$ with a universal Gaussian tail.
  • The limiting law is independent of the detailed entry correlations and depends on the diagonal data $X,Y$ only through the free-convolution density at zero, up to the imposed normalization.
  • The ensemble is invertible with overwhelming probability, with quantitative control on the smallest singular value matching the i.i.d. Gaussian case.
  • The real orthogonal analogue has a different edge: $\mathbb{P}(N\lambda_1(M)\le r)=1-e^{-r^2/2-r}+O(N^{-c})$, showing the universality class depends on the base field.
  • The proof corrects and strengthens the short-time universality statement for the symmetrized flow used in prior work, adding a regularity hypothesis that the earlier statement omitted.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • Editorial inference: the same symmetrization strategy should extend to sums of $k$ independent Haar-conjugated deterministic matrices, with the main new check being the density condition near zero for the $k$-fold free convolution.
  • Editorial inference: the real/complex contrast suggests the edge law is governed by whether the symmetrized flow has repulsion between the smallest positive and negative singular values, so other symmetry classes would plausibly produce their own explicit laws.
  • Editorial inference: because the edge scale is fixed by the single number $\rho(0)=1/\pi$, one can rescale $X$ and $Y$ to tune that value and empirically observe the edge scale change, giving a direct numerical probe of the theorem's mechanism.
  • Editorial inference: the quantitative bound implies an immediate invertibility estimate for this correlated ensemble, which could be useful in algorithms involving sums of unitarily conjugated data matrices.
Share X Bluesky LinkedIn Reddit HN

Signed reviews

No signed human review yet.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 5 minor

Summary. The paper studies the least singular value of M = R* X T + U* Y V, where X and Y are deterministic diagonal matrices and R, T, U, V are independent Haar-distributed unitary matrices. The main result, Theorem 2.1, states that under assumptions (1)–(7) of Section 2.2, the rescaled least singular value N λ1(M) satisfies P(N λ1(M) ≤ r) = 1 - e^{-r^2} + O(N^{-c}) uniformly in r ≥ 0, with c > 0 an absolute constant. The proof follows the dynamical method of Che and Landon [32]: a carefully chosen flow on the unitary group produces a system of SDEs for the singular values of the symmetrized 2N × 2N Hermitian matrix; a local law (Section 4) and eigenvector estimates (Section 5) control the drift; well-posedness is proved in Section 6; and Section 7 compares the SDE to a symmetrized Dyson Brownian motion, invoking a short-time universality result from [33]. The final comparison to the Gaussian least singular value uses the explicit distribution of the latter.

Significance. If the central claim is established, the paper gives a substantial extension of least-singular-value universality from independent-entry ensembles to a model with strongly correlated entries, with a polynomially explicit error rate that is uniform in r. The proof is detailed and largely self-contained except for the imported short-time universality statement: it includes a local law, a well-posedness analysis, and explicit rigidity and coupling estimates. The authors are transparent about the restrictiveness of Assumption (7), and they provide two sufficient conditions in Appendix C. The main significance is therefore conditional on the unresolved status of Proposition 7.5, which is the load-bearing external input of the paper.

major comments (3)
  1. [Section 7, Proposition 7.5 and Remark 7.6] The proof of Proposition 7.5 is not supplied in the manuscript. Remark 7.6 explicitly concedes that the original statement of [33, Theorem 3.2] omitted a necessary hypothesis used in its proof, and that the corrected statement is justified only by saying that one may follow the old proof up to a scaling of the particles by π ρ̂_{t0}(0), with the verification of this scaling delegated to [32, Theorem 2.4]. Since Theorem 7.7 and hence Theorem 2.1 inherit Proposition 7.5 directly, this missing proof is load-bearing. The reader has no way to check that the corrected hypothesis (7.17) is sufficient and that no further missing condition remains in the old argument. A complete, self-contained proof of Proposition 7.5, or a reference to a published version containing the full corrected proof, is required.
  2. [Section 7, Eqs. (7.17)–(7.18)] The paper asserts, but does not demonstrate, that the regularity condition (7.17) implies the matching condition π ρ̂_{t0}(0) = 1 + O(N^{-c}) under the parameter constraints g N^σ ≤ t0 ≤ N^{-σ} G^2. This matching is the reason the particle system can be coupled to the Gaussian reference process at time t0, so the derivation is not a routine detail. The interaction between the choices of g, G, σ, ω0, ω1 and the assumption (2.12) should be written out explicitly, including how the constants in (7.17) enter the error rate. Without this verification, the short-time comparison step is incomplete.
  3. [Section 7, verification of (g,G)-regularity] The statement that the hypotheses of Proposition 7.5 are verified with overwhelming probability for the singular values of M(0) by Corollary 5.9 is made without specifying the parameters g and G, the precise interval of energies, or the constants involved in Definition 7.4. Since Corollary 5.9 is proved under the bulk condition (2.12) and with a specific rate, the choice of g and G must be compatible with the constraints in (7.18). This compatibility should be stated explicitly rather than left implicit.
minor comments (5)
  1. [Sections 2.2 and 4.4] The name "Stieltjes" is misspelled as "Stietjes" in at least two places (near Eq. (2.6) and Section 4.4).
  2. [Section 4.3, proof of Lemma 4.8] In the proof of Lemma 4.8, after deriving the second equation of (4.41), the text says "To prove the second equation"; this should read "To prove the first equation" (or "the remaining equation").
  3. [Section 2.2, Eq. (2.10)] The definition of y*_k as an infimum over an equality condition is clean for continuous µ2, but for measures with atoms the condition should be a weak inequality (with the usual quantile convention) to avoid ambiguity; this is a minor notational point.
  4. [Appendix A, near Eq. (A.9)] The phrase "noting that (dˆB_ij)(dˆB_kl) = δ_il δ_jk" omits the differential dt in the quadratic covariation; the computation is standard, but the notation is imprecise.
  5. [Appendix B, Theorem B.1] The real-case formula 1 - e^{-r^2/2 - r} is stated without a reference for the exact distribution of the least singular value of a real Gaussian matrix; citing the precise source, for example [72, Theorem 1.3] as indicated in the text above the theorem, would help the reader.

Circularity Check

0 steps flagged · score 0.0 of 10

No circularity: the Gaussian comparison imports a distinct short-time universality result; the corrected Proposition 7.5 is an external dependency and a verification risk, not an input re-labeled as a prediction.

full rationale

No circularity is present in the derivation chain. The central result, Theorem 2.1, is not an input: the only normalization that sets the Gaussian scale is the explicit hypothesis in (2.12), 'c≤ρ(x)≤C, ρ(0)=1/π', which the authors state 'is necessary to make the scale of the smallest singular value match that of the analogous Gaussian ensemble' and note could be removed by rescaling; it is a stated condition, not a fitted parameter renamed as a prediction. The load-bearing comparison, Proposition 7.5, is taken from the authors' prior work, with the paper saying 'The following proposition is essentially [33, Theorem 3.2]', but it is a distinct statement about a deterministic matrix V that is (g,G)-regular with respect to the free convolution m3, not a restatement of Theorem 2.1; the present model enters only when Corollary 5.9 verifies that regularity. Remark 7.6 openly concedes that 'the statement of [33, Theorem 3.2] omits a necessary hypothesis used in its proof' and supplies a corrected statement whose proof is only sketched, with part delegated to [32, Theorem 2.4]. That is an unverified external dependency, hence a genuine correctness/verification risk, but it is not circular: no equation is defined in terms of the target distribution, no fitted parameter is called a prediction, and no uniqueness theorem from the same authors is invoked to declare a choice forced. Under the rubric, a cited prior result with stated assumptions that do not include the target result counts as independent support, so the score is 0.

Assumptions & free parameters 0 free parameters · 10 assumptions · 0 invented entities

The central claim rests on a long list of domain assumptions (1)-(7) on the deterministic matrices X and Y, plus a key imported theorem. No numerical parameters are fitted to data; the constants in the proof are chosen by hand but the argument works for a range of values. No new physical entities are introduced. The most consequential entries are the rigidity of Y (assumption (5)), the sub-linear edge density of mu_2 (assumption (6)), and especially the free convolution density condition rho(0)=1/pi (assumption (7)), which sets the constant in the limiting law.

assumptions (10)
  • domain assumption Deterministic diagonal matrices X and Y have entries bounded by C0: 0 <= x_i, y_i <= C0 (Section 2.2, (2.2)).
    Bounds all norms of X and Y used throughout the proof.
  • domain assumption Uniform boundedness of the Stieltjes transform of Y: sup_{E, eta >= N^{-1+a}} |m_Y(E+i eta)| <= C_a (Section 2.2, (2.7)).
    Prevents accumulation of y_i; used in Proposition C.1 to bound A and A_hat.
  • domain assumption Empirical measures mu_X, mu_Y converge weakly to compactly supported mu_1, mu_2, and at least one of mu_1, mu_2 has a bounded Stieltjes transform (Section 2.2, assumption (2)).
    Needed to apply [15, Theorem 4.4] for the strong local law at small energies in Theorem 5.6.
  • domain assumption Neither mu_1^sym nor mu_2^sym is a single point mass, and at least one is supported at more than two points (Section 2.2, assumption (3)).
    Ensures free convolution has a continuous density and avoids degenerate edge cases.
  • domain assumption Polynomial convergence of the Stieltjes transform of mu_X to mu_1 with rate N^{-c_X} (Section 2.2, (2.8)).
    Used in Section 5.2 to compare finite-N and limiting Stieltjes transforms.
  • domain assumption Rigidity of the y_k: |y_k - y_k^*| <= N^{-1+c} for all k (Section 2.2, (2.9)).
    Essential for the counting bound I(alpha, eta) >= c N eta^{2-c} in Corollary 5.5, which underpins eigenvector delocalization.
  • domain assumption The limiting measure mu_2 has a continuous density satisfying mu_2([x-h,x+h]) >= h^{2-c} near its edges (Section 2.2, (2.11)).
    Technical edge condition used in the same counting argument as rigidity.
  • domain assumption The free convolution mu_1^sym boxplus mu_2^sym has a density rho on a neighborhood of zero with c <= rho <= C and rho(0)=1/pi (Section 2.2, (2.12)).
    Sets the scale of the least singular value to the Gaussian scale; without rho(0)=1/pi the constant in Theorem 2.1 changes. Called difficult to check; sufficient conditions are in Appendix C.
  • domain assumption Short-time universality of the symmetrized Dyson Brownian motion flow (Proposition 7.5, based on [33, Theorem 3.2] with a corrected hypothesis).
    The central comparison with the Gaussian ensemble is imported from the authors' prior work [33]; the current paper states and sketches the correction but does not give a fully self-contained proof.
  • standard math Free convolution subordination equations (4.51) have a unique analytic solution and continuous extensions (proved in [23, Theorem 4.1], [20, Remark 2.4], [22, Corollary 8]).
    Background theorem used in Sections 4.4 and 5.2.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Universality of the least singular value for the sum of random matrices." pith.science (2026). https://pith.science/paper/PXDI3KZX

@misc{pith2026190804060,
  author       = {Pith},
  title        = {Pith review of: Universality of the least singular value for the sum of random matrices},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/PXDI3KZX}},
  note         = {Machine review of arXiv:1908.04060}
}
abstract

We consider the least singular value of $M = R^* X T + U^* YV$, where $R,T,U,V$ are independent Haar-distributed unitary matrices and $X, Y$ are deterministic diagonal matrices. Under weak conditions on $X$ and $Y$, we show that the limiting distribution of the least singular value of $M$, suitably rescaled, is the same as the limiting distribution for the least singular value of a matrix of i.i.d. gaussian random variables. Our proof is based on the dynamical method used by Che and Landon to study the local spectral statistics of sums of Hermitian matrices.

Figures

Figures reproduced from arXiv: 1908.04060 by the authors.

Figure 1
Figure 1. Simulated distribu￾tion of the least singular value of the real model, with the ele￾ments of X and Y chosen uni￾formly from [0, 1], matrix size N = 200, and 2 × 104 samples [PITH_FULL_IMAGE:figures/full_fig_p030_1.png] view at source ↗

Discussion (0). Continue with ORCID to comment.

Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Optimal Lower Bound on the Least Singular Value of the Shifted Ginibre Ensemble

    math.PR 2019-08 accept novelty 6.0 of 10

    For shifted real or complex Ginibre matrices near the spectral edge, the least singular value has optimal tail probability of order x in the complex case and square-root x with a Gaussian imaginary-part damping in the...

Reference graph

Works this paper leans on

81 extracted references · 77 canonical work pages · cited by 1 Pith paper

  1. [32]

    Che and B

    Z. Che and B. Landon. Local spectral statistics of the addition of random matrices. Probability Theory and Related Fields, 175(1-2):579–654, 2019

  2. [33]

    Che and P

    Z. Che and P. Lopatto. Universality of the least singular value for sparse random matrices. Electronic Journal of Probability, 24, 2019

  3. [1]

    E. Abbe, A. Shpilka, and A. Wigderson. Reed–Muller codes for random erasures and errors. IEEE Transactions on Information Theory , 61(10):5229–5252, 2015

  4. [2]

    Adamczak, O

    R. Adamczak, O. Gu´ edon, A. Litvak, A. Pajor, and N. Tomczak-Jaegermann. Smallest singular value of random matrices with independent columns. Comptes Rendus Mathematique , 346(15-16):853–856, 2008

  5. [3]

    Spectral Statistics of Sparse Random Graphs with a General Degree Distribution

    B. Adlam and Z. Che. Spectral statistics of sparse random graphs with a general degree distribution. Preprint arXiv:1509.03368, 2015

  6. [4]

    Aggarwal

    A. Aggarwal. Bulk universality for generalized Wigner matrices with few moments. Probability Theory and Related Fields, 173(1-2):375–432, 2019

  7. [5]

    Aggarwal, P

    A. Aggarwal, P. Lopatto, and H.-T. Yau. GOE statistics for L´ evy matrices.arXiv preprint arXiv:1806.07363, 2018

  8. [6]

    Quadratic vector equations on complex upper half-plane

    O. Ajanki, L. Erd˝ os, and T. Kr¨ uger. Quadratic vector equations on complex upper half-plane.Preprint arXiv:1506.05095, 2015

Show all 81 references
  1. [7]

    Ajanki, L

    O. Ajanki, L. Erd˝ os, and T. Kr¨ uger. Singularities of solutions to quadratic vector equations on the complex upper half plane. Communications on Pure and Applied Mathematics , 70(9), 2017

  2. [8]

    Ajanki, L

    O. Ajanki, L. Erd˝ os, and T. Kr¨ uger. Universality for general Wigner-type matrices.Probability Theory and Related Fields, 169(3-4):667–727, 2017

  3. [9]

    Anari, C

    N. Anari, C. Daskalakis, W. Maass, C. Papadimitriou, A. Saberi, and S. Vempala. Smoothed analysis of discrete tensor decomposition and assemblies of neurons. In Advances in Neural Information Processing Systems, pages 10857–10867, 2018

  4. [10]

    G. W. Anderson, A. Guionnet, and O. Zeitouni.An Introduction to Random Matrices. Cambridge University Press, 2010

  5. [11]

    Z. Bao, L. Erd˝ os, and K. Schnelli. Local stability of the free additive convolution. Journal of Functional Analysis, 271(3):672–719, 2016

  6. [12]

    Z. Bao, L. Erd˝ os, and K. Schnelli. Convergence rate for spectral distribution of addition of random matrices. Advances in Mathematics, 319:251–291, 2017

  7. [13]

    Z. Bao, L. Erd˝ os, and K. Schnelli. Local law of addition of random matrices on optimal scale. Communi- cations in Mathematical Physics , 349(3):947–990, 2017

  8. [14]

    Z. Bao, L. Erd˝ os, and K. Schnelli. Spectral rigidity for addition of random matrices at the regular edge. arXiv preprint arXiv:1708.01597 , 2017

  9. [15]

    Z. Bao, L. Erd˝ os, and K. Schnelli. Local single ring theorem on optimal scale. The Annals of Probability , 47(3):1270–1334, 2019

  10. [16]

    Basak and M

    A. Basak and M. Rudelson. Invertibility of sparse non-Hermitian matrices. Advances in Mathematics , 310:426–483, 2017

  11. [17]

    Bauerschmidt, J

    R. Bauerschmidt, J. Huang, A. Knowles, and H.-T. Yau. Bulk eigenvalue statistics for random regular graphs. The Annals of Probability , 45(6A):3626–3663, 2017

  12. [18]

    Bauerschmidt, J

    R. Bauerschmidt, J. Huang, and H.-T. Yau. Local Kesten–McKay law for random regular graphs. Communications in Mathematical Physics , pages 1–114, 2016. 34 ZILIANG CHE AND PATRICK LOPATTO

  13. [19]

    Bauerschmidt, A

    R. Bauerschmidt, A. Knowles, and H.-T. Yau. Local semicircle law for random regular graphs. Comm. Pure Appl. Math. , 70:1898–1960, Oct. 2017

  14. [20]

    S. T. Belinschi. A note on regularity for free convolutions. Ann. Inst. Henri Pointcar` e Probab. Stat., 42(5):635–648, 2006

  15. [21]

    S. T. Belinschi. The lebesgue decomposition of the free additive convolution of two probability distributions. Probability Theory and Related Fields , 142(1-2):125–150, 2008

  16. [22]

    S. T. Belinschi. l∞-boundedness of density for free additive convolutions. Rev. Roumaine Math. Pures Appl., 59(2):173–184, 2014

  17. [23]

    S. T. Belinschi and H. Bercovici. A new approach to subordination results in free probability. J. Anal. Math., 101(1):357–365, 2007

  18. [24]

    Bhaskara, M

    A. Bhaskara, M. Charikar, A. Moitra, and A. Vijayaraghavan. Smoothed analysis of tensor decompositions. In Proceedings of the forty-sixth annual ACM symposium on Theory of computing , pages 594–603. ACM, 2014

  19. [25]

    P. Biane. Representations of symmetric groups and free probability. Advances in Mathematics, 138(1):126– 181, 1998

  20. [26]

    Bose and W

    A. Bose and W. Hachem. Smallest singular value and limit eigenvalue distribution of a class of non- Hermitian random matrices with statistical application. Journal of Multivariate Analysis , page 104623, 2020

  21. [27]

    Bourgade

    P. Bourgade. Extreme gaps between eigenvalues of Wigner matrices. arXiv preprint arXiv:1812.10376 , 2018

  22. [28]

    Bourgade, L

    P. Bourgade, L. Erd˝ os, H.-T. Yau, and J. Yin. Fixed energy universality for generalized Wigner matrices. Comm. Pure Appl. Math. , Dec. 2015

  23. [29]

    Bourgade, L

    P. Bourgade, L. Erd˝ os, H.-T. Yau, and J. Yin. Universality for a class of random band matrices. Advances in Theoretical and Mathematical Physics , 21(3):739–800, 2017

  24. [30]

    Bourgade, F

    P. Bourgade, F. Yang, H.-T. Yau, and J. Yin. Random band matrices in the delocalized phase, II: Generalized resolvent estimates. Journal of Statistical Physics , pages 1–33, 2019

  25. [31]

    Bourgade, H.-T

    P. Bourgade, H.-T. Yau, and J. Yin. Random band matrices in the delocalized phase, I: Quantum unique ergodicity and universality. Communications on Pure and Applied Mathematics , 73(7):1526–1596, 2020

  26. [34]

    Cipolloni, L

    G. Cipolloni, L. Erd˝ os, and D. Schr¨ oder. Edge universality for non-Hermitian random matrices.arXiv preprint arXiv:1908.00969, 2019

  27. [35]

    Cipolloni, L

    G. Cipolloni, L. Erd˝ os, and D. Schr¨ oder. Optimal lower bound on the least singular value of the shifted Ginibre ensemble. arXiv preprint arXiv:1908.01653 , 2019

  28. [36]

    B. Collins. Moments and cumulants of polynomial random variables on unitary groups, the Itzykson–Zuber integral, and free probability. International Mathematics Research Notices, 2003(17):953–982, 2003

  29. [37]

    N. Cook. Lower bounds for the smallest singular value of structured random matrices. The Annals of Probability, 46(6):3442–3500, 2018

  30. [38]

    F. J. Dyson. A Brownian-motion model for the eigenvalues of a random matrix. J. Math. Phys. , 3(6):1191– 1198, 1962

  31. [39]

    A. Edelman. Eigenvalues and condition numbers of random matrices. SIAM J. Matrix Anal. SIAM J. Matrix Anal. Appl. , 9:543–560, 1988

  32. [40]

    P´ ech´ e, J

    Erd˝ os, S. P´ ech´ e, J. A. Ramirez, and B. Schlein. Bulk universality for Wigner matrices.Comm. Pure Appl. Math., 63(7):895–925, 2010

  33. [41]

    Erd˝ os, A

    L. Erd˝ os, A. Knowles, H.-T. Yau, and J. Yin. Spectral statistics of Erd˝ os–R´ enyi graphs II: eigenvalue spacing and the extreme eigenvalues. Comm. Math. Phys. , 314(3):587–640, 2012

  34. [42]

    Erd˝ os, A

    L. Erd˝ os, A. Knowles, H.-T. Yau, and J. Yin. Spectral statistics of Erd˝ os–R´ enyi graphs I: local semicircle law. Ann. Probab., 41(3B):2279–2375, 2013

  35. [43]

    Erd˝ os and H.-T

    L. Erd˝ os and H.-T. Yau. Gap universality of generalized Wigner andβ-ensembles. J. Eur. Math., 17(8):1927– 2036, 2015

  36. [44]

    Erd˝ os and H.-T

    L. Erd˝ os and H.-T. Yau. Dynamical approach to random matrix theory. Courant Lecture Notes in Mathematics, 28, 2017

  37. [45]

    Erd˝ os, H.-T

    L. Erd˝ os, H.-T. Yau, and B. Schlein. Universality of random matrices and local relaxation flow. Invent. Math., 185(1):75–119, 2011. UNIVERSALITY OF THE LEAST SINGULAR VALUE FOR THE SUM OF RANDOM MATRICES 35

  38. [46]

    Erd¨ os, J

    L. Erd¨ os, J. A. Ram´ ırez, B. Schlein, T. Tao, V. Van, and H.-T. Yau. Bulk universality for Wigner Hermitian matrices with subexponential decay. Mathematical Research Letters, 17(4), 2010

  39. [47]

    Erd˝ os, B

    L. Erd˝ os, B. Schlein, and H.-T. Yau. Universality of random matrices and local relaxation flow. Invent. Math., 185(1):75–119, 2011

  40. [48]

    Erd˝ os, B

    L. Erd˝ os, B. Schlein, H.-T. Yau, and J. Yin. The local relaxation flow approach to universality of the local statistics for random matrices. Annales de l’I.H.P. Probabilit´ es et statistiques, 48(1):1–46, 2012

  41. [49]

    Erd˝ os, H.-T

    L. Erd˝ os, H.-T. Yau, and J. Yin. Bulk universality for generalized Wigner matrices.Probab. Theory Related Fields, 154(1-2):341–407, 2012

  42. [50]

    Feldheim and S

    O. Feldheim and S. Sodin. A universality result for the smallest eigenvalues of certain sample covariance matrices. Geometric And Functional Analysis , 20(1):88–123, 2010

  43. [51]

    G¨ otze, A

    F. G¨ otze, A. Naumov, and A. Tikhomirov. On minimal singular values of random matrices with correlated entries. Random Matrices: Theory and Applications , 4(02):1550006, 2015

  44. [52]

    Huang and B

    J. Huang and B. Landon. Local law and mesoscopic fluctuations of Dyson Brownian motion for general β and potential. arXiv preprint arXiv:1612.06306 , 2016

  45. [53]

    Huang, B

    J. Huang, B. Landon, and H.-T. Yau. Bulk universality of sparse random matrices. J. Math. Phys. , 56(12):123301, 2015

  46. [54]

    V. Kargin. A concentration inequality and a local law for the sum of two random matrices. Probability Theory and Related Fields , 154(3-4):677–702, 2012

  47. [55]

    V. Kargin. Subordination for the sum of two random matrices. The Annals of Probability, 43(4):2119–2150, 2015

  48. [56]

    Kopel, S

    P. Kopel, S. ORourke, and V. Vu. Random matrix products: Universality and least singular values. Annals of Probability, 48(3):1372–1410, 2020

  49. [57]

    Landon, P

    B. Landon, P. Sosoe, and H.-T. Yau. Fixed energy universality of dyson brownian motion. Advances in Mathematics, 346:1137–1332, 2019

  50. [58]

    Landon and H.-T

    B. Landon and H.-T. Yau. Convergence of local statistics of Dyson Brownian motion. Comm. Math. Phys. , 355:9491000, Nov. 2017

  51. [59]

    J. O. Lee, K. Schnelli, B. Stetler, and H.-T. Yau. Bulk universality for deformed Wigner matrices. Ann. Probab., 44(3):2349–2425, 2016

  52. [60]

    J. O. Lee and J. Yin. A necessary and sufficient condition for edge universality of Wigner matrices. Duke Mathematical Journal, 163(1):117–173, 2014

  53. [61]

    Litvak and O

    A. Litvak and O. Rivasplata. Smallest singular value of sparse random matrices. Studia Mathematica, 212(3), Jun. 2011

  54. [62]

    G. V. Livshyts. The smallest singular value of heavy-tailed not necessarily i.i.d. random matrices via random rounding. arXiv preprint arXiv:1811.07038 , 2018

  55. [63]

    H. Maassen. Addition of freely independent random variables. J. Funct. Anal., 106:409–438, 1992

  56. [64]

    Pastur and V

    L. Pastur and V. Vasilchuk. On the law of addition of random matrices. Communications in Mathematical Physics, 214(2):249–286, 2000

  57. [65]

    Rebrova and K

    E. Rebrova and K. Tikhomirov. Coverings of random ellipsoids, and invertibility of matrices with i.i.d. heavy-tailed entries. Israel Journal of Mathematics , 227(2):507–544, 2018

  58. [66]

    Rudelson

    M. Rudelson. Invertibility of random matrices: norm of the inverse. Annals of Mathematics, pages 575–600, 2008

  59. [67]

    Rudelson and R

    M. Rudelson and R. Vershynin. The Littlewood–Offord problem and invertibility of random matrices. Advances in Mathematics, 218(2):600–633, 2008

  60. [68]

    Rudelson and R

    M. Rudelson and R. Vershynin. Smallest singular value of a random rectangular matrix. Communications on Pure and Applied Mathematics: A Journal Issued by the Courant Institute of Mathematical Sciences , 62(12):1707–1739, 2009

  61. [69]

    Rudelson and R

    M. Rudelson and R. Vershynin. Non-asymptotic theory of random matrices: extreme singular values. In Proceedings of the International Congress of Mathematicians 2010 , pages 1576–1602. World Scientific, 2010

  62. [70]

    Speicher

    R. Speicher. Free convolution and the random sum of matrices. Publications of the Research Institute for Mathematical Sciences, 29(5):731–744, 1993

  63. [71]

    Spielman and S

    D. Spielman and S. Teng. Smoothed analysis of algorithms. In Proceedings of the International Congress of Mathematicians 2002 , pages 1576–1602. Higher Ed. Press, 2002

  64. [72]

    Tao and V

    T. Tao and V. Vu. Random matrices: the distribution of the smallest singular value. Geometric and Functional Analysis, 20(1):260–297, 2010. 36 ZILIANG CHE AND PATRICK LOPATTO

  65. [73]

    Tao and V

    T. Tao and V. H. Vu. Inverse Littlewood–Offord theorems and the condition number of random discrete matrices. Annals of Mathematics , pages 595–632, 2009

  66. [74]

    K. Tatarko. An upper bound on the smallest singular value of a square random matrix. Journal of Complexity, 48:119–128, 2018

  67. [75]

    Tikhomirov

    K. Tikhomirov. The limit of the smallest singular value of random matrices with i.i.d. entries. Advances in Mathematics, 284:1–20, 2015

  68. [76]

    Tikhomirov

    K. Tikhomirov. The smallest singular value of random rectangular matrices with no moment assumptions on entries. Israel Journal of Mathematics , 212(1):289–314, 2016

  69. [77]

    Tikhomirov

    K. Tikhomirov. Invertibility via distance for noncentered random matrices with continuous distributions. Random Structures & Algorithms , 2020

  70. [78]

    Vershynin

    R. Vershynin. Concentration inequalities for random tensors. arXiv preprint arXiv:1905.00802 , 2019

  71. [79]

    Voiculescu

    D. Voiculescu. Limit laws for random matrices and free products.Inventiones mathematicae, 104(1):201–220, 1991

  72. [80]

    R. Wilcox. Exponential operators and parameter differentiation in quantum physics. Journal of Mathe- matical Physics, 8(4):962–982, 1967

  73. [81]

    Yang and J

    F. Yang and J. Yin. Random band matrices in the delocalized phase, III: Averaging fluctuations. arXiv preprint arXiv:1807.02447, 2018

Pith tools

Reviewed August 14, 2026 · model on record in the stance chip above.