Recent Papers

Brauer's height zero conjecture, Annals of Math. (to appear, joint work with G. Malle, G. Navarro, and A. A. Schaeffer Fry).

Uniform character bounds for finite classical groups, Annals of Math. (to appear, joint work with M. Larsen).

Character levels and character bounds for finite classical groups, Invent. Math. 235 (2024), 151 - 210 (joint work with R. M. Guralnick and M. Larsen).

The fields of values of characters of degree not divisible by p, Forum of Math. Pi 9 (2021), e2, 1 - 28 (joint work with G. Navarro).

Character levels and character bounds, Forum of Math. Pi 8 (2020), e2, 81 pages (joint work with R. M. Guralnick and M. Larsen).

Probabilistic Waring problems for finite simple groups, Annals of Math. 190 (2019), 561 - 608 (joint work with M. Larsen and A. Shalev).

Character bounds for finite groups of Lie type, Acta Math. 221 (2018), 1 - 57 (joint work with R. Bezrukavnikov, M. Liebeck, and A. Shalev).

Surjective word maps and Burnside's p^aq^b theorem, Invent. Math. 213 (2018), 589 - 695 (joint work with R. M. Guralnick, M. W. Liebeck, E. O'Brien, and A. Shalev).

On Alperin's lower bound for the number of Brauer characters, Transf. Groups 28 (2023), 1205 - 1120 (joint work with G. Malle and G. Navarro).

Representations and tensor product growth, Intern. Math. Res. Notices IMRN (2023), no. 14, 12477 - 12511 (joint work with M. Larsen and A. Shalev).

Degrees and fields of values of irreducible characters, Europ. J. Math. 9 (2023), no. 2, Paper No. 37, 17 pp. (joint work with N. N. Hung).

Character bounds for regular semisimple elements and asymptotic results on Thompson's conjecture, Math. Z. 303 (2023), no. 2, Paper 47, 45 pages (joint work with M. Larsen and J. Taylor).

Primes and degrees of Brauer characters, Bull. Lond. Math. Soc. 55 (2023), 723 - 731 (joint work with G. Navarro).

Nonsolvable groups have a large proportion of vanishing elements, Israel J. Math. 254 (2023), 229 - 242 (joint work with A. Moreto).

Products of derangements in simple permutation groups, Forum of Math. Sigma 10 (2022), e83, 1 - 30 (joint work with M. Larsen and A. Shalev).

Decomposition numbers and global properties, J. Algebra 607 (2022), part A, 607 - 617 (joint work with G. Navarro).

Hall-Higman type theorems for exceptional groups of Lie type. I, J. Algebra 607 (2022), part A, 755 - 794 (joint work with A. E. Zalesski).

Odd-degree rational irreducible characters, Acta Math. Vietnam 47 (2022), 293 - 304 (joint work with Hung P. Tong-Viet).

Hypergeometric sheaves and finite symplectic and unitary groups, Cambridge J. Math. 9 (2021), 577 - 691 (joint work with N. Katz).

Monodromy groups of Kloosterman and hypergeometric sheaves, Geom. Funct. Analysis 31 (2021), 562 - 662 (joint work with N. Katz).

Exponential sums and total Weil representations of finite symplectic and unitary groups, Proc. Lond. Math. Soc. 122 (2021), 745 - 807 (joint work with N. Katz).

McKay graphs for alternating groups and classical groups, Trans. Amer. Math. Soc. 374 (2021), 5651 - 5676 (joint work with M. W. Liebeck and A. Shalev).

Rigid local systems and finite general linear groups, Math. Z. 298 (2021), 1293 - 1321 (joint work with N. Katz).

Character ratios for exceptional groups of Lie type, Int. Math. Res. Not. IMRN 2021, no. 16, 12054 - 12076 (joint work with M. W. Liebeck).

On irreducible products of characters, J. Algebra 573 (2021), 38 - 55 (joint work with G. Navarro).

On the diameters of McKay graphs for finite simple groups, Israel J. Math. 241 (2021), 449 - 464 (joint work with M. Liebeck and A. Shalev).

Lusztig induction, unipotent support, and character bounds, Trans. Amer. Math. Soc. 373 (2020), 8637--8776 (joint work with J. Taylor).

Character ratios, representation varieties and random generation of finite groups of Lie type, Advances in Math. 374 (2020), 107386, 39 pp. (joint work with M. Liebeck and A. Shalev).

A rigid local system with monodromy group the big Conway group 2.Co_1 and two others with monodromy group the Suzuki group 6.Suz, Trans. Amer. Math. Soc. 373 (2020), 2007 - 2044 (joint work with N. Katz and A. Rojas-Leon).

Irreducible restrictions of representations of symmetric and alternating groups in small characteristics, Advances in Math. 369 (2020), 107184, 66pp. (joint work with A. S. Kleshchev and L. Morotti).

Moments of Weil representations of finite special unitary groups, J. Algebra 561 (2020), 237 - 255 (joint work with N. Katz).

Tensor product Markov chains, J. Algebra 561 (2020), 17 - 83 (joint work with G. Benkart, P. Diaconis, and M. W. Liebeck).

Irreducible induction and nilpotent subgroups in finite groups, J. Algebra 561 (2020), 200 - 214 (joint work with Z. Halasi, G. Navarro, and A. Maroti).

Decomposition numbers and local properties, J. Algebra 558 (2020), 620 - 639 (joint work with G. Navarro).

Sectional rank and cohomology, J. Algebra 558 (2020), 434 - 452 (joint work with R. M. Guralnick).

Irreducible restrictions of representations of alternating groups in small characteristics: reduction theorems, Rep. Theory 24 (2020), 115 - 150 (joint work with A. S. Kleshchev and L. Morotti).

Lower bounds for dimensions of irreducible representations of symmetric groups, Proc. Amer. Math. Soc. 148 (2020), 1439 - 1445 (joint work with A. S. Kleshchev and L. Morotti).

Rigid local systems with monodromy group the Conway group Co_2, Int. J. Number Theory 16 (2020), 341 - 360 (joint work with N. Katz and A. Rojas-Leon).

The average character degree and an improvement of the Ito-Michler theorem, J. Algebra 550 (2020), 86 - 107 (joint work with N. N. Hung).

Rigid local systems with monodromy group the Conway group Co_3, J. Number Theory 206 (2020), 1 - 23 (joint work with N. Katz and A. Rojas-Leon).

Unitary t-groups, J. Math. Soc. Japan 72 (2020), 909 - 921 (joint work with E. Bannai, G. Navarro, and N. Rizo).

Local systems and finite unitary and symplectic groups, Advances in Math. 358 (2019), 106859, 37 pp. (joint work with N. Katz).

Sylow subgroups, exponents, and character values, Trans. Amer. Math. Soc. 372 (2019), 4263 - 4291 (joint work with G. Navarro).

Fields of values of odd-degree irreducible characters, Advances in Math. 354 (2019), 106757, 26 pp. (joint work with I. M. Isaacs, M. W. Liebeck, and G. Navarro).

Rigid local systems and finite symplectic groups, Finite Fields Appl. 59 (2019), 134 - 174 (joint work with N. Katz).

Order of products of elements in finite groups, J. Lond. Math. Soc. 99 (2019), 535 - 552 (joint work with A. Beltran, R. Lyons, A. Moreto, G. Navarro, and A. Saez).

Irreducible restrictions of representations of symmetric groups in small characteristics: Reduction theorems, Math. Z. 293 (2019), 677 - 723 (joint work with A. S. Kleshchev and L. Morotti).

Brauer correspondent blocks with one simple module, Trans. Amer. Math. Soc. 371 (2019), 903 - 922 (joint work with G. Navarro and C. Vallejo).

On real and rational characters in blocks, Int. Math. Res. Not. IMRN 2019, no. 7,1955 - 1973 (joint work with G. Navarro and G. R. Robinson).

Rigid local systems and alternating groups, Tunisian J. Math. 1 (2019), 295 - 320 (joint work with R. M. Guralnick and N. Katz).

Symmetric and alternating powers of Weil representations of finite symplectic groups, Bull. Inst. Math. Acad. Sinica 13 (2018), 443 - 461 (joint work with R. M. Guralnick and K. Magaard).

Characters and Sylow 2-subgroups of maximal class revisited, J. Pure Appl. Alg. 222 (2018), 3721 - 3732 (joint work G. Navarro and B. Sambale).

On 2-Brauer characters of odd degree, Math. Z. 290 (2018), 469 - 483 (joint work with G. Navarro).

Irreducible characters of 3'-degree of finite symmetric, general linear and unitary groups, J. Pure Appl. Algebra 222 (2018), 2199 - 2228 (joint work with E. Giannelli and J. Tent).

Finite groups with many values in a column of the character table, J. Alg. Appl. 17 (2018), 1850196 (20 pages) (joint work with H. P. Tong-Viet).

Adequate subgroups and indecomposable modules, J. Eur. Math. Soc. (JEMS) 19 (2017), 1231 - 1291 (joint work with R. M. Guralnick and F. Herzig).

Some conjectures on Frobenius' character sum, Bull. Lond. Math. Soc. 49 (2017), 895 - 902 (joint work with A. Shalev).

Coprime actions and correspondences of Brauer characters, Proc. Lond. Math. Soc. 114 (2017), 589 - 613 (joint work with G. Navarro and B. Spaeth).

``Finite Simple Groups: Thirty Years of the Atlas and Beyond'', Contemp. Math., vol. 694, AMS, 2017 (co-editor with M. Bhargava, R. M. Guralnick, G. Hiss, and K. Lux).

Restriction of odd degree characters and natural correspondences, Int. Math. Res. Not. IMRN 2017, no. 20, 6089 - 6118 (joint work with E. Giannelli, A. S. Kleshchev, and G. Navarro).

Character restrictions and multiplicities in symmetric groups, J. Algebra 478 (2017), 271 - 282 (joint work with I. M. Isaacs, G. Navarro, and J. B. Olsson).

Irreducible characters of even degree and normal Sylow 2-subgroups, Math. Proc. Cambridge Philos. Soc. 162 (2017), 353 - 365 (joint work with N. N. Hung).

The alpha-invariant and Thompson's conjecture, Forum of Math. Pi 4 (2016), e5, 28 pages.

Real groups and Sylow 2-subgroups, Adv. Math. 299 (2016), 331 - 360 (joint work with G. Navarro).

Representations of the alternating group which are irreducible over subgroups. II, Amer. J. Math. 138 (2016), 1383 - 1423 (joint work with A. S. Kleshchev and P. Sin).

Non-abelian Littlewood-Offord inequalities, Adv. Math. 302 (2016), 1233 - 1250 (joint work with Van H. Vu).

Finite groups with odd Sylow normalizers, Proc. Amer. Math. Soc. 144 (2016), 5129 - 5139 (joint work with R. M. Guralnick and G. Navarro).

Irreducible representations of odd degree, Math. Annalen 365 (2016), 1155 - 1185 (joint work with G. Navarro).

Arithmetic results on orbits of linear groups, Trans. Amer. Math. Soc. 368 (2016), 2415 - 2467 (joint work with M. Giudici, M. Liebeck, C. Praeger, and J. Saxl).

Nilpotent and abelian Hall subgroups in finite groups, Trans. Amer. Math. Soc. 368 (2016), 2497 - 2513 (joint work with A. Beltran, M. Felipe, G. Malle, A. Moreto, G. Navarro, L. Sanus, and R. Solomon).

An Erdos-Ko-Rado theorem for finite 2-transitive groups, Europ. J. Comb. 55 (2016), 100 - 118 (joint work with K. Meagher and P. Spiga).

Adequate groups of low degree, Algebra Number Theory 9 (2015), 77 - 147 (joint work with R. M. Guralnick and F. Herzig).

A refined Waring problem for finite simple groups, Forum of Mathematics, Sigma 3 (2015), e6, 22 pages (joint work with M. Larsen).

Effective results on the Waring problem for finite simple groups, Amer. J. Math. 137 (2015), 1401- 1430 (joint work with R. M. Guralnick).

Weil representations of finite general linear groups and finite special linear groups, Pacific J. Math. 279 (2015), 481 - 498.

p-parts of character degrees, J. Lond. Math. Soc. 92 (2015), 483 - 497 (joint work with M. L. Lewis, G. Navarro, and H. P. Tong-Viet).

Lifting in Frattini covers and a characterization of finite solvable groups, J. Reine Angew. Math. 708 (2015), 49 - 72 (joint work with R. M. Guralnick).

Real ordinary characters and real Brauer characters, Trans. Amer. Math. Soc. 367 (2015), 1273-1312.

Abelian Sylow subgroups in a finite group. II, J. Algebra 421 (2015), 3 - 11 (joint work with G. Navarro and R. Solomon).

Subgroup structure and representations of finite and algebraic groups, Vietnam J. Math. 43 (2015), 501 - 513.

McKay natural correspondences on characters, Algebra Number Theory 8 (2014), 1839 - 1856 (joint work with G. Navarro and C. Vallejo).

On fully ramified Brauer characters, Adv. Math. 257 (2014), 248 - 265 (joint work with G. Navarro and B. Spaeth).

Brauer characters and rationality, Math. Z. 276 (2014), 1101 - 1112 (joint work with G. Navarro).

Abelian Sylow subgroups in a finite group. I, J. Algebra 398 (2014), 519 - 526 (joint work with G. Navarro).

Finite groups with two conjugacy classes of p-elements and related questions for p-blocks, Bull. London Math. Soc. 46 (2014), 305 - 314 (joint work with B. Kuelshammer, G. Navarro, and B. Sambale).

p-parts of Brauer character degrees, J. Algebra 403 (2014), 426 - 438 (joint work with G. Navarro and H. P. Tong-Viet).

Representation of finite groups: conjectures, reductions, and applications, Acta Math. Vietnam. 39 (2014), 87 - 109.

Groups with exactly one irreducible character of degree divisible by p, Algebra Number Theory 8 (2014) 397 - 428 (joint work with D. Goldstein, R. M. Guralnick, M. L. Lewis, A. Moreto, and G. Navarro).

Characters of relative p'-degree over normal subgroups, Annals of Math. 178 (2013), 1135 - 1171 (joint work with G. Navarro).

Zeros of real irreducible characters of finite groups, Algebra Number Theory 7 (2013), 567 - 593 (joint work with S. Marinelli).

Waring problem for finite quasisimple groups, Int. Math. Res. Notices 2013, no. 10, 2323 - 2348 (joint work with M. Larsen and A. Shalev).

The largest irreducible representations of simple groups, Proc. London Math. Soc. 106 (2013), 65 - 96 (joint work with M. Larsen and G. Malle).

Conjugacy action, induced representations and the Steinberg square for simple groups of Lie type, Proc. London Math. Soc. 106 (2013), 908 - 930 (joint work with G. Heide, J. Saxl, and A. E. Zaleskii).

Products of conjugacy classes in finite and algebraic simple groups, Adv. Math. 234 (2013), 618 - 652 (joint work with R. M. Guralnick and G. Malle).

Groups whose same degree characters are Galois conjugate, Israel J. Math. 198 (2013), 283 - 331 (joint work with S. Dolfi and G. Navarro; with an appendix by T. Breuer and K. Lux).

``Quadratic and Higher Degree Forms'', Developments in Mathematics, vol. 31, Springer, 2013 (co-editor with K. Alladi, M. Bhargava, and D. Savitt).

Representation growth in positive characteristic and conjugacy classes of maximal subgroups, Duke Math. J. 161 (2012), 107 - 137 (joint work with R. M. Guralnick and M. Larsen).

A problem of Kollar and Larsen on finite linear groups and crepant resolutions, J. Europ. Math. Soc. 14 (2012), 605 - 657 (joint work with R. M. Guralnick).

Brauer's height zero conjecture for the 2-blocks of maximal defect, J. Reine Angew. Math. 669 (2012), 225 - 247 (joint work with G. Navarro).

Small-dimensional projective representations of symmetric and alternating groups, Algebra Number Theory 6 (2012), 1773 - 1816 (joint work with A. S. Kleshchev).

Products of squares in finite simple groups, Proc. Amer. Math. Soc. 140 (2012), 21 - 33 (joint work with M. Liebeck, E. O'Brien, and A. Shalev).

Cycle indices for finite orthogonal groups of even characteristic, Trans. Amer. Math. Soc. 364 (2012), 2539 - 2566 (joint work with J. Fulman and J. Saxl).

Degrees and p-rational characters, Bull. London Math. Soc. 44 (2012), 1246 - 1250 (joint work with G. Navarro).

Waring problem for finite simple groups, Annals of Math. 174 (2011), 1885 - 1950 (joint work with M. Larsen and A. Shalev).

First cohomology groups of Chevalley groups in cross characteristic, Annals of Math. 174 (2011), 543 - 559 (joint work with R. M. Guralnick).

A reduction theorem for the Alperin weight conjecture, Invent. Math. 184 (2011), 529 - 565 (joint work with G. Navarro).

Commutators in finite quasisimple groups, Bull. London Math. Soc. 43 (2011), 1079 - 1092 (joint work with M. Liebeck, E. O'Brien, and A. Shalev).

Real class sizes and real character degrees, Math. Proc. Camb. Philos. Soc. 150 (2011), 47 - 71 (joint work with R. M. Guralnick and G. Navarro)

The Ore conjecture, J. Europ. Math. Soc. 12 (2010), 939 -1008 (joint work with M. Liebeck, E. O'Brien, and A. Shalev) (Early version).

Degrees of rational characters of finite groups, Adv. Math. 224 (2010), 1121 - 1142 (joint work with G. Navarro).

Representations of general linear groups which are irreducible over subgroups, Amer. J. Math. 132 (2010), 425 - 473 (joint work with A. S. Kleshchev).

Dual pairs of finite classical groups in cross characteristic, Contemp. Math. 524 (2010), pp. 161 - 179.

On p-Brauer characters of p'-degree and self-normalizing Sylow p-subgroups, J. Group Theory 13 (2010), 785 - 797 (joint work with G. Navarro).

Non-vanishing elements of finite groups, J. Algebra 323 (2010), 540 - 545 (joint work with S. Dolfi, G. Navarro, E. Pacifici, and L. Sanus).

Brauer characters of prime power degrees and conjugacy classes of prime power lengths, Alg. Colloq. 17 (2010), 541- 548 (joint work with W. Willems).

Groups with just one character degree divisible by a given prime, Trans. Amer. Math. Soc. 361 (2009), 6521 - 6547 (joint work with I. M. Isaacs, A. Moreto, and G. Navarro).

Representations of finite special linear groups in non-defining characteristic, Adv. Math. 220 (2009), 478 - 504 (joint work with A. S. Kleshchev) ( Early version, arXiv:0810.0849v1 [math.RT]).

Real characters and degrees, Israel J. Math. 171 (2009), 157 - 173 (joint work with G. Navarro and L. Sanus).

On the restriction of cross characteristic representations of ^{2}F_{4}(q) to proper subgroups, Archiv Math. 93 (2009), 415 - 423 (joint work with F. Himstedt and H. N. Nguyen).

Symmetric powers and a problem of Kollar and Larsen, Invent. Math. 174 (2008), 505 - 554 (joint work with R. M. Guralnick) (Early version, arXiv:0810.0853v1 [math.RT]).

Hall-Higman type theorems for semisimple elements of finite classical groups, Proc. London Math. Soc. 97 (2008), 623 - 668 (joint work with A. E. Zalesskii) (Early version, arXiv:0810.0855v1 [math.RT]).

Rational irreducible characters and rational conjugacy classes in finite groups, Trans. Amer. Math. Soc. 360 (2008), 2443 - 2465 (joint work with G. Navarro).

Primes dividing the degrees of the real characters of finite groups, Math. Z. 259 (2008), 755 - 774 (joint work with S. Dolfi and G. Navarro).

Brauer characters with cyclotomic field of values, J. Pure Appl. Alg. 212 (2008), 628 - 635 (joint work with G. Navarro and A. Turull).

Prime divisors of character degrees, J. Group Theory 11 (2008), 341 - 356 (joint work with A. Moreto).

Cross characteristic representations of ^{3}D_{4}(q) are reducible over proper subgroups, with an appendix by F. Himstedt, J. Group Theory 11 (2008), 657 - 668 (joint work with H. N. Nguyen).

Groups with two real Brauer characters, J. Algebra 307 (2007), 891 - 898 (joint work with G. Navarro and L. Sanus).

On the Navarro-Willems conjecture for blocks of finite groups, J. Pure Appl. Algebra 208 (2007), 481 - 484 (joint work with C. Bessenrodt, G. Navarro, and J. Olsson) (dvi file), (Addendum).

p-rational characters and self-normalizing Sylow p-subgroups, Represent. Theory 11 (2007), 84 - 94 (joint work with G. Navarro and A. Turull).

Mutually unbiased bases and orthogonal decompositions of Lie algebras, Quantum Information and Communication, 7 (2007), 371 - 382 (joint work with P. Boykin, M. Sitharam, and P. Wocjan).

Characters of p'-degree with cyclotomic field of values, Proc. Amer. Math. Soc. 134 (2006), 2833 - 2837 (joint work with G. Navarro).

Rational Brauer characters, Math. Annalen 335 (2006), 675 - 686 (joint work with G. Navarro).

Finite groups admitting grassmannian 4-designs, J. Algebra 306 (2006), 227 - 243.

Real conjugacy classes in algebraic groups and finite groups of Lie type, J. Group Theory 8 (2005), 291 - 315 (joint work with A. E. Zalesski).

Decompositions of small tensor powers and Larsen's conjecture, Represent. Theory 9 (2005), 138 - 208 (joint work with R. M. Guralnick) (dvi file).

Rank 3 permutation modules for finite classical groups, J. Algebra 291 (2005), 551 - 606 (joint work with P. Sin).

The non-coprime k(GV)-problem, J. Algebra 293 (2005), 185-242 (joint work with R. M. Guralnick).

Unipotent elements of finite groups of Lie type and realization fields of their complex representations, J. Algebra 271 (2004), 327 - 390 (joint work with A. E. Zalesskii).

On restrictions of modular spin representations of symmetric and alternating groups, Trans. Amer. Math. Soc. 356 (2004), 1971-1999 (joint work with A. S. Kleshchev).

Cross characteristic representations of even characteristic symplectic groups, Trans. Amer. Math. Soc. 356 (2004), 4969 - 5023 (joint work with R. M. Guralnick).

The modulo 2 structure of rank 3 permutation modules for odd characteristic symplectic groups, J. Algebra 268 (2003), 463 - 483 (joint work with J. M. Lataille and P. Sin).

Finite simple unisingular groups of Lie type, J. Group Theory 6 (2003), 271 - 310 (joint work with R. M. Guralnick).

Low dimensional representations of finite quasisimple groups, Proceedings of the London Math. Soc. Symposium ``Groups, Geometries, and Combinatorics'', Durham, July 2001, A. A. Ivanov et al eds., World Scientific, 2003, N. J. 277 - 294.

Irreducibility of tensor squares, symmetric squares, and alternating squares, Pacific J. Math. 202 (2002), 379 - 427 (joint work with K. Magaard and G. Malle).

Mod p reducibility of unramified representations of finite groups of Lie type, Proc. London Math. Soc. 84 (2002), 439 - 472 (joint work with A. E. Zalesskii).

Reducibility modulo p of complex representations of finite groups of Lie type: Asymptotical result and small characteristic case, Proc. Amer. Math. Soc. 130 (2002), 3177 - 3184 (joint work with A. E. Zalesskii).

Cross characteristic representations of symplectic groups and unitary groups, J. Algebra 257 (2002), 291 - 347; Addendum, J. Algebra 299 (2006), 443 - 446, (joint work with R. M. Guralnick, K. Magaard, and J. Saxl).

Irreducible tensor products of representations of quasi-simple finite groups of Lie type, in: Modular Representation Theory of Finite Groups (M. Collins, B. Parshall, L. Scott, eds.) Walter de Gruyter, Berlin 2001, 239 - 262 (joint work with K. Magaard).

Symmetric squares, spherical designs, and lattice minima, J. Algebra 240 (2001), 185 - 208 (joint work with W. Lempken and B. Schroeder).

Some aspects of finite linear groups: A survey, J. Math. Sciences 100 (2000), 1893 - 1914 (joint work with A. E. Zalesskii). (dvi file)

Low-dimensional representations of special linear groups in cross characteristic, Proc. London Math. Soc. 78 (1999), 116 - 138 (joint work with R. Guralnick).

Symplectic group lattices, Trans. Amer. Math. Soc. 351 (1999), 2101 -- 2139 (joint work with R. Scharlau).

Lower bounds for the minima of certain symplectic and unitary group lattices, Amer. J. Math. 121 (1999), 889 - 918 (joint work with N. Dummigan).

Globally irreducible representations of SL(3,q) and SU(3,q), Israel J. Math. 109 (1999), 225 - 251.

Modular representations of GL(3,p), symmetric squares, and mod-p cohomology of GL(3,Z), J. Algebra 222 (1999), 376 - 399 (joint work with A. Ash).

Globally irreducible lattices, Contemp. Math. 249 (1999), 97 - 111.

Congruences for certain theta series, J. Number Theory 77 (1998), 86 - 105 (joint work with N. Dummigan).

The p-intersection subgroups in quasi-simple and almost simple finite groups, J. Algebra 207 (1998), 1 - 42 (joint work with P. Fleischmann and W. Lempken).

The primitive p-Frobenius groups, Proc. Amer. Math. Soc. 126 (1998), 1337 - 1343 (joint work with P. Fleischmann and W. Lempken).