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BEZ NEAL RICHARD(ベズ ニール リチャード)
理工学研究科 数理電子情報部門 | 教授(特定プロジェクト教員) |
理学部 数学科 |
業績情報
■ 論文- A note on ubiquity of geometric Brascamp–Lieb data
Neal Bez; Anthony Gauvan; Hiroshi Tsuji
Bulletin of the London Mathematical Society, 巻:57, 号:1, 開始ページ:302, 終了ページ:314, 2024年12月
Abstract
Relying substantially on work of Garg, Gurvits, Oliveira and Wigderson, it is shown that geometric Brascamp–Lieb data are, in a certain sense, dense in the space of feasible Brascamp–Lieb data. This addresses a question raised by Bennett and Tao in their recent work on the adjoint Brascamp–Lieb inequality.
Wiley, 研究論文(学術雑誌)
DOI:https://doi.org/10.1112/blms.13198
DOI ID:10.1112/blms.13198, ISSN:0024-6093, eISSN:1469-2120 - Boundary Strichartz estimates and pointwise convergence for orthonormal systems
Neal Bez; Shinya Kinoshita; Shobu Shiraki
Transactions of the London Mathematical Society, 巻:11, 号:1, 2024年12月
Abstract
We consider maximal estimates associated with fermionic systems. Firstly, we establish maximal estimates with respect to the spatial variable. These estimates are certain boundary cases of the many‐body Strichartz estimates pioneered by Frank, Lewin, Lieb and Seiringer. We also prove new maximal‐in‐time estimates, thereby significantly extending work of Lee, Nakamura and the first author on Carleson's pointwise convergence problem for fermionic systems.
Wiley, 研究論文(学術雑誌)
DOI:https://doi.org/10.1112/tlm3.70002
DOI ID:10.1112/tlm3.70002, ISSN:2052-4986, eISSN:2052-4986 - Stability of hypercontractivity, the logarithmic Sobolev inequality, and Talagrand's cost inequality
Neal Bez; Shohei Nakamura; Hiroshi Tsuji
Journal of Functional Analysis, 巻:285, 号:10, 開始ページ:110121, 終了ページ:110121, 2023年11月, [査読有り]
Elsevier BV, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.jfa.2023.110121
DOI ID:10.1016/j.jfa.2023.110121, ISSN:0022-1236 - Revisiting the Rellich inequality
Neal Bez; Shuji Machihara; Tohru Ozawa
Mathematische Zeitschrift, 巻:303, 号:2, 2023年01月, [査読有り]
Springer Science and Business Media LLC, 研究論文(学術雑誌)
DOI:https://doi.org/10.1007/s00209-022-03203-4
DOI ID:10.1007/s00209-022-03203-4, ISSN:0025-5874, eISSN:1432-1823 - Higher order transversality in harmonic analysis
Jonathan Bennett; Neal Bez
RIMS Kôkyûroku Bessatsu, 巻:B88, 開始ページ:75, 終了ページ:103, 2021年, [査読有り] - Strichartz estimates for orthonormal families of initial data and weighted oscillatory integral estimates
Neal Bez; Sanghyuk Lee; Shohei Nakamura
Forum of Mathematics, Sigma, 巻:9, 2021年, [査読有り]Abstract
We establish new Strichartz estimates for orthonormal families of initial data in the case of the wave, Klein–Gordon and fractional Schrödinger equations. Our estimates extend those of Frank–Sabin in the case of the wave and Klein–Gordon equations, and generalize work of Frank et al. and Frank–Sabin for the Schrödinger equation. Due to a certain technical barrier, except for the classical Schrödinger equation, the Strichartz estimates for orthonormal families of initial data have not previously been established up to the sharp summability exponents in the full range of admissible pairs. We obtain the optimal estimates in various notable cases and improve the previous results.
The main novelty of this paper is our derivation and use of estimates for weighted oscillatory integrals, which we combine with an approach due to Frank and Sabin. Our weighted oscillatory integral estimates are, in a certain sense, rather delicate endpoint versions of known dispersive estimates with power-type weights of the form or
$|\xi |^{-\lambda }$
, where
$(1 + |\xi |^2)^{-\lambda /2}$
. We achieve optimal decay rates by considering such weights with appropriate
$\lambda \in \mathbb {R}$
. For the wave and Klein–Gordon equations, our weighted oscillatory integral estimates are new. For the fractional Schrödinger equation, our results overlap with prior work of Kenig–Ponce–Vega in a certain regime. Our contribution to the theory of weighted oscillatory integrals has also been influenced by earlier work of Carbery–Ziesler, Cowling et al., and Sogge–Stein.
$\lambda \in \mathbb {C}$
Finally, we provide some applications of our new Strichartz estimates for orthonormal families of data to the theory of infinite systems of Hartree type, weighted velocity averaging lemmas for kinetic transport equations, and refined Strichartz estimates for data in Besov spaces.
Cambridge University Press (CUP), 研究論文(学術雑誌)
DOI:https://doi.org/10.1017/fms.2020.64
DOI ID:10.1017/fms.2020.64, eISSN:2050-5094 - On the nonlinear Brascamp-Lieb inequality
Jonathan Bennett; Neal Bez; Stefan Buschenhenke; Michael Cowling; Taryn Flock
Duke Mathematical Journal, 巻:169, 開始ページ:3291, 終了ページ:3338, 2020年, [査読有り] - Maximal estimates for the Schrodinger equation with orthonormal initial data
Neal Bez; Sanghyuk Lee; Shohei Nakamura
Selecta Mathematica, 巻:26, 号:52, 2020年, [査読有り]
Springer Science and Business Media LLC, 研究論文(学術雑誌)
DOI:https://doi.org/10.1007/s00029-020-00582-6
DOI ID:10.1007/s00029-020-00582-6, ISSN:1022-1824, eISSN:1420-9020 - A supersolutions perspective on hypercontractivity
Yosuke Aoki; Jonathan Bennett; Neal Bez; Shuji Machihara; Kosuke Matsuura; Shobu Shiraki
Annali di Matematica Pura ed Applicata, 巻:199, 開始ページ:2105, 終了ページ:2116, 2020年, [査読有り] - Inhomogeneous Strichartz estimates in some critical cases
Neal Bez; Jayson Cunanan; Sanghyuk Lee
Proceedings of the American Mathematical Society, 巻:148, 開始ページ:639, 終了ページ:652, 2020年, [査読有り] - Hardy type inequalities with spherical derivatives
Neal Bez; Shuji Machihara; Tohru Ozawa
SN Partial Differential Equations and Applications, 巻:1, 号:5, 2020年, [査読有り] - On the Strichartz estimates for orthonormal systems of initial data with regularity
Neal Bez; Younghun Hong; Sanghyuk Lee; Shohei Nakamura; Yoshihiro Sawano
Advances in Mathematics, 巻:354, 号:106736, 開始ページ:106736, 終了ページ:106736, 2019年, [査読有り]
Elsevier BV, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.aim.2019.106736
DOI ID:10.1016/j.aim.2019.106736, ISSN:0001-8708 - Smoothing estimates for velocity averages with radial data
Neal Bez; Jayson Cunanan
RIMS Kokyuroku Bessatsu, 巻:B74, 開始ページ:33, 終了ページ:46, 2019年, [査読有り] - Remarks on the Mizohata-Takeuchi conjecture and related problems
Neal Bez; Mitsuru Sugimoto
Advanced Studies in Pure Mathematics, 巻:81, 開始ページ:1, 終了ページ:12, 2019年, [査読有り] - Generating monotone quantities for the heat equation
J. Bennett; N. Bez
Journal für die reine und angewandte Mathematik, 巻:756, 開始ページ:37, 終了ページ:63, 2019年, [査読有り] - Estimates for the kinetic transport equation in hyperbolic Sobolev spaces
Jonathan Bennett; Neal Bez; Susana Gutiérrez; Sanghyuk Lee
Journal des Mathematiques Pures et Appliquees, 巻:114, 開始ページ:1, 終了ページ:28, 2018年06月, [査読有り]
We establish smoothing estimates in the framework of hyperbolic Sobolev spaces for the velocity averaging operator ρ of the solution of the kinetic transport equation. If the velocity domain is either the unit sphere or the unit ball, then, for any exponents q and r, we find a characterisation of the exponents β+ and β−, except possibly for an endpoint case, for which D+ β+ D− β− ρ is bounded from space–velocity Lx,v 2 to space–time Lt qLx r. Here, D+ and D− are the classical and hyperbolic derivative operators, respectively. In fact, we shall provide an argument which unifies these velocity domains and the velocity averaging estimates in either case are shown to be equivalent to mixed-norm bounds on the cone multiplier operator acting on L2. We develop our ideas further in several ways, including estimates for initial data lying in certain Besov spaces, for which a key tool in the proof is the sharp ℓp decoupling theorem recently established by Bourgain and Demeter. We also show that the level of permissible smoothness increases significantly if we restrict attention to initial data which are radially symmetric in the spatial variable.
Elsevier Masson SAS, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.matpur.2018.03.007
DOI ID:10.1016/j.matpur.2018.03.007, ISSN:0021-7824, SCOPUS ID:85045703051 - A sharp k-plane strichartz inequality for the schrödinger equation
Jonathan Bennett; Neal Bez; Taryn C. Flock; Susana Gutiérrez; Marina Iliopoulou
Transactions of the American Mathematical Society, 巻:370, 号:8, 開始ページ:5617, 終了ページ:5633, 2018年, [査読有り]
We prove that ‖X(|u|2)‖L3 t,ℓ ≤ C‖f‖2L2(ℝ2),where u(x, t) is the solution to the linear time-dependent Schrödinger equation on ℝ2with initial datum f and X is the (spatial) X-ray transform on R2In particular, we identify the best constant C and show that a datum f is an extremiser if and only if it is a gaussian. We also establish bounds of this type in higher dimensions d, where the X-ray transform is replaced by the k-plane transform for any 1 ≤ k ≤ d − 1. In the process we obtain sharp L2(μ) bounds on Fourier extension operators associated with certain high-dimensional spheres involving measures μ supported on natural “co-k-planarity” sets.
American Mathematical Society, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1090/tran/7309
DOI ID:10.1090/tran/7309, ISSN:0002-9947, SCOPUS ID:85047105131 - Stability of the Brascamp-Lieb constant and applications
J. Bennett; N. Bez; T. Flock; S. Lee
American Journal of Mathematics, 巻:140, 開始ページ:543, 終了ページ:569, 2018年, [査読有り] - Stability of trace theorems on the sphere
N. Bez; C. Jeavons; T. Ozawa; M. Sugimoto
Journal of Geometric Analysis, 巻:28, 開始ページ:1456, 終了ページ:1476, 2018年, [査読有り] - Smoothing estimates for the kinetic transport equation at the critical regularity
Neal Bez; Jayson Cunanan; Sanghyuk Lee
SIAM Journal on Mathematical Analysis, 巻:50, 号:2, 開始ページ:2280, 終了ページ:2294, 2018年, [査読有り]
We prove smoothing estimates for velocity averages of the kinetic transport equation in hyperbolic Sobolev spaces at the critical regularity, leading to a complete characterization of the allowable regularity exponents. Such estimates will be deduced from some mixed-norm estimates for the cone multiplier operator at a certain critical index. Our argument is not particular to the geometry of the cone and we illustrate this by establishing analogous estimates for the paraboloid.
Society for Industrial and Applied Mathematics Publications, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1137/17M1148852
DOI ID:10.1137/17M1148852, ISSN:1095-7154, SCOPUS ID:85047342233 - Behaviour of the Brascamp-Lieb constant
Jonathan Bennett; Neal Bez; Michael G. Cowling; Taryn C. Flock
BULLETIN OF THE LONDON MATHEMATICAL SOCIETY, 巻:49, 号:3, 開始ページ:512, 終了ページ:518, 2017年06月, [査読有り]
Recent progress in multilinear harmonic analysis naturally raises questions about the local behaviour of the best constant (or bound) in the general Brascamp-Lieb inequality as a function of the underlying linear transformations. In this paper we prove that this constant is continuous, but is not in general differentiable.
WILEY, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1112/blms.12049
DOI ID:10.1112/blms.12049, ISSN:0024-6093, eISSN:1469-2120, Web of Science ID:WOS:000402144800014 - On sharp bilinear Strichartz estimates of Ozawa-Tsutsumi type
Jonathan Bennett; Neal Bez; Chris Jeavons; Nikolaos Pattakos
JOURNAL OF THE MATHEMATICAL SOCIETY OF JAPAN, 巻:69, 号:2, 開始ページ:459, 終了ページ:476, 2017年04月, [査読有り]
We provide a comprehensive analysis of sharp bilinear estimates of Ozawa Tsutsumi type for solutions u of the free Schrodinger equation, which give sharp control on vertical bar u vertical bar(2) in classical Sobolev spaces. In particular, we generalise their estimates in such a way that provides a unification with some sharp bilinear estimates proved by Carneiro and Planchon Vega, via entirely different methods, by seeing them all as special cases of a one-parameter family of sharp estimates. The extremal functions are solutions of the Maxwell-Boltzmann functional equation and hence Gaussian. For u(2) we argue that the natural analogous results involve certain dispersive Sobolev norms; in particular, despite the validity of the classical Ozawa Tsutsumi estimates for both vertical bar u vertical bar(2) and u(2) in the classical Sobolev spaces, we show that Gaussians are not extremisers in the latter case for spatial dimensions strictly greater than two.
MATH SOC JAPAN, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.2969/jmsj/06920459
DOI ID:10.2969/jmsj/06920459, ISSN:0025-5645, Web of Science ID:WOS:000401401300001 - A conjecture regarding optimal Strichartz estimates for the wave equation
N. Bez; C. Jeavons; T. Ozawa; H. Saito
Trends in Mathematics (New Trends in Analysis and Interdisciplinary Applications), 2017年, [査読有り] - Optimal constants and extremisers for some smoothing estimates
N. Bez; M. Sugimoto
Journal d'Analyse Mathematique, 巻:131, 開始ページ:159, 終了ページ:187, 2017年, [査読有り] - Sharpness of the brascamp-lieb inequality in lorentz spaces
Neal Bez; Sanghyuk Lee; Shohei Nakamura; Yoshihiro Sawano
Electronic Research Announcements in Mathematical Sciences, 巻:24, 開始ページ:53, 終了ページ:63, 2017年, [査読有り]
We provide necessary conditions for the refined version of the Brascamp-Lieb inequality where the input functions are allowed to belong to Lorentz spaces, thereby establishing the sharpness of the range of Lorentz exponents in the subcritical case. Using similar considerations, some sharp refinements of the Strichartz estimates for the kinetic transport equation are established.
American Mathematical Society, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.3934/era.2017.24.006
Scopus:https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85020907812&origin=inward
Scopus Citedby:https://www.scopus.com/inward/citedby.uri?partnerID=HzOxMe3b&scp=85020907812&origin=inward
DOI ID:10.3934/era.2017.24.006, ISSN:1935-9179, SCOPUS ID:85020907812 - SOME SHARP BILINEAR SPACE-TIME ESTIMATES FOR THE WAVE EQUATION
Neal Bez; Chris Jeavons; Tohru Ozawa
MATHEMATIKA, 巻:62, 号:3, 開始ページ:719, 終了ページ:737, 2016年, [査読有り]
We prove a family of sharp bilinear space-time estimates for the halfwave propagator e(it root-Delta). As a consequence, for radially symmetric initial data, we establish sharp estimates of this kind for a range of exponents beyond the classical range.
LONDON MATH SOC, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1112/S0025579316000012
DOI ID:10.1112/S0025579316000012, ISSN:0025-5793, eISSN:2041-7942, Web of Science ID:WOS:000375948100005 - Extremisers for the trace theorem on the sphere
Neal Bez; Shuji Machihara; Mitsuru Sugimoto
MATHEMATICAL RESEARCH LETTERS, 巻:23, 号:3, 開始ページ:633, 終了ページ:647, 2016年, [査読有り]
We find all extremisers for the trace theorem on the sphere. We also provide a sharp extension for functions belonging to certain Sobolev spaces with angular regularity.
INT PRESS BOSTON, INC, 英語, 研究論文(学術雑誌)
ISSN:1073-2780, eISSN:1945-001X, Web of Science ID:WOS:000388457200003 - A survey on optimal smoothing estimates and trace theorems
N. Bez; M. Sugimoto
Advances in Mathematics (China), 巻:45, 開始ページ:801, 終了ページ:816, 2016年, [査読有り] - Applications of the Funk-Hecke theorem to smoothing and trace estimates
Neal Bez; Hiroki Saito; Mitsuru Sugimoto
ADVANCES IN MATHEMATICS, 巻:285, 開始ページ:1767, 終了ページ:1795, 2015年11月, [査読有り]
For a wide class of Kato-smoothing estimates with radial weights, the Funk-Hecke theorem is used to generate a new expression for the optimal constant in terms of the Fourier transform of the weight, from which several applications are given. For example, we are able to easily establish a unified theorem, assuming natural power-like asymptotic estimates for the Fourier transform of the weight, from which many well-studied smoothing estimates immediately follow, as well as sharpness of the decay and smoothness exponents. Furthermore, observing that the weight has an everywhere positive Fourier transform in many well-studied cases, our approach allows sharper information regarding the optimal constant and extremisers, substantially extending earlier work of Simon. These observations are very closely related to the Mizohata-Takeuchi conjecture regarding the equivalence of weighted L-2 bounds for the Fourier extension operator on the sphere and the uniform boundedness of the X-ray transform of the weight. For radial weights, this has been independently established by Barcelo-Ruiz-Vega and Carbery-Soria; we provide a short alternative proof in three and higher dimensions of this equivalence when the Fourier transform of the weight is positive, with the optimal relationship between constants. Finally, our approach works for the closely connected trace theorems on the sphere where analogous results are given, including the optimal constant and characterisation of extremisers for the inhomogeneous H-s (R-d) -> L-2 (Sd-1) trace theorem. (C) 2015 Elsevier Inc. All rights reserved.
ACADEMIC PRESS INC ELSEVIER SCIENCE, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.aim.2015.08.025
DOI ID:10.1016/j.aim.2015.08.025, ISSN:0001-8708, eISSN:1090-2082, Web of Science ID:WOS:000376417800048 - Optimal Forward and Reverse Estimates of Morawetz and Kato-Yajima Type with Angular Smoothing Index
Neal Bez; Mitsuru Sugimoto
JOURNAL OF FOURIER ANALYSIS AND APPLICATIONS, 巻:21, 号:2, 開始ページ:318, 終了ページ:341, 2015年04月, [査読有り]
For the solution of the free Schrodinger equation, we obtain the optimal constants and characterise extremisers for forward and reverse smoothing estimates which are global in space and time, contain a homogeneous and radial weight in the space variable, and incorporate a certain angular regularity. This will follow from a more general result which permits analogous sharp forward and reverse smoothing estimates and a characterisation of extremisers for the solution of the free Klein-Gordon and wave equations. The nature of extremisers is shown to be sensitive to both the dimension and the size of the smoothing index relative to the dimension. Furthermore, in four spatial dimensions and certain special values of the smoothing index, we obtain an exact identity for each of these evolution equations.
SPRINGER BIRKHAUSER, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1007/s00041-014-9371-0
DOI ID:10.1007/s00041-014-9371-0, ISSN:1069-5869, eISSN:1531-5851, Web of Science ID:WOS:000351174800004 - Some Recent Progress on Sharp Kato-type Smoothing Estimates
Neal Bez; Mitsuru Sugimoto
COMPLEX ANALYSIS AND DYNAMICAL SYSTEMS VI, PT 1: PDE, DIFFERENTIAL GEOMETRY, RADON TRANSFORM, 巻:653, 開始ページ:41, 終了ページ:50, 2015年, [査読有り]
Space-time estimates of the type
parallel to Psi(x, del) exp(-it Delta)f parallel to L-t,x((RxRd))2 <= C parallel to f parallel to(L2(Rd)),
where Psi(x, del) = < x >(-s) (s >= 1), Psi(x, del) = vertical bar x vertical bar(a-1) vertical bar del vertical bar(a) (1-d/2 <a<1/2) or Psi(x, del) = < x >(-s) vertical bar del vertical bar(1/2) (s>1/2), are often called smoothing estimates, and there is a vast literature surrounding these estimates. Simon [22] initiated the study of optimal constants for smoothing estimates by obtaining them in the special cases Psi(x, del) = vertical bar x vertical bar(-1) and Psi(x, del) - < x >(-1) vertical bar del vertical bar(1/2). In this article, recent progress on optimal constants and their extremisers for more general cases are discussed based on recent works [4] and [5] by the authors.
AMER MATHEMATICAL SOC, 英語, 研究論文(国際会議プロシーディングス)
DOI:https://doi.org/10.1090/conm/653/13177
DOI ID:10.1090/conm/653/13177, ISSN:0271-4132, Web of Science ID:WOS:000371648700004 - Sharp sobolev-strichartz estimates for the free Schrödinger propagator
Neal Bez; Chris Jeavons; Nikolaos Pattakos
Trends in Mathematics, 巻:2, 開始ページ:281, 終了ページ:288, 2015年, [査読有り]
We consider gaussian extremisability of sharp linear Sobolev-Strichartz estimates and closely related sharp bilinear Ozawa-Tsutsumi estimates for the free Schrödinger equation.
Springer International Publishing, 英語, 研究論文(国際会議プロシーディングス)
DOI:https://doi.org/10.1007/978-3-319-12577-0-33
DOI ID:10.1007/978-3-319-12577-0-33, ISSN:2297-024X, SCOPUS ID:84959159490 - A SHARP SOBOLEV-STRICHARTZ ESTIMATE FOR THE WAVE EQUATION
Neal Bez; Chris Jeavons
ELECTRONIC RESEARCH ANNOUNCEMENTS IN MATHEMATICAL SCIENCES, 巻:22, 開始ページ:46, 終了ページ:54, 2015年, [査読有り]
We calculate the the sharp constant and characterize the extremal initial data in (H) over dot(3/4) x H-1/4 for the L-4 Sobolev-Strichartz estimate for the wave equation in four spatial dimensions.
AMER INST MATHEMATICAL SCIENCES, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.3934/era.2015.22.46
DOI ID:10.3934/era.2015.22.46, ISSN:1935-9179, Web of Science ID:WOS:000361819700005 - Flow Monotonicity and Strichartz Inequalities
Jonathan Bennett; Neal Bez; Marina Iliopoulou
INTERNATIONAL MATHEMATICS RESEARCH NOTICES, 号:19, 開始ページ:9415, 終了ページ:9437, 2015年, [査読有り]
We identify complete monotonicity properties underlying a variety of well-known sharp Strichartz inequalities in euclidean space.
OXFORD UNIV PRESS, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1093/imrn/rnu230
DOI ID:10.1093/imrn/rnu230, ISSN:1073-7928, eISSN:1687-0247, Web of Science ID:WOS:000366499400008 - Optimal constant for a smoothing estimate of critical index
N. Bez; M. Sugimoto
Trends in Mathematics (Fourier Analysis), 開始ページ:1, 終了ページ:7, 2014年, [査読有り] - On the Strichartz Estimates for the Kinetic Transport Equation
Jonathan Bennett; Neal Bez; Susana Gutierrez; Sanghyuk Lee
COMMUNICATIONS IN PARTIAL DIFFERENTIAL EQUATIONS, 巻:39, 号:10, 開始ページ:1821, 終了ページ:1826, 2014年, [査読有り]
We show that the endpoint Strichartz estimate for the kinetic transport equation is false in all dimensions. We also present an alternative approach to proving the non-endpoint cases using multilinear analysis.
TAYLOR & FRANCIS INC, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1080/03605302.2013.850880
DOI ID:10.1080/03605302.2013.850880, ISSN:0360-5302, eISSN:1532-4133, Web of Science ID:WOS:000341003700001 - A note on magnitude bounds for the mask coefficients of the interpolatory Dubuc-Deslauriers subdivision scheme
H. E. Bez; N. Bez
LMS JOURNAL OF COMPUTATION AND MATHEMATICS, 巻:17, 号:1, 開始ページ:226, 終了ページ:232, 2014年, [査読有り]
We analyse the mask associated with the 2n-point interpolatory Dubuc-Deslauriers subdivision scheme S-a[n]. Sharp bounds are presented for the magnitude of the coefficients a(2i-1)([n]) of the mask. For scales i is an element of [1, root n] it is shown that vertical bar a(2i-1)([n])vertical bar is comparable to i(-1), and for larger power scales, exponentially decaying bounds are obtained. Using our bounds, we may precisely analyse the summability of the mask as a function of n by identifying which coefficients of the mask contribute to the essential behaviour in n, recovering and refining the recent result of Deng-Hormann Zhang that the operator norm of S-a[n] on l(infinity) grows logarithmically in n.
CAMBRIDGE UNIV PRESS, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1112/S1461157013000363
DOI ID:10.1112/S1461157013000363, ISSN:1461-1570, Web of Science ID:WOS:000349291700013 - New minimal bounds for the derivatives of rational Bezier paths and rational rectangular Bezier surfaces
H. E. Bez; N. Bez
APPLIED MATHEMATICS AND COMPUTATION, 巻:225, 開始ページ:475, 終了ページ:479, 2013年12月, [査読有り]
New minimal bounds are derived for the magnitudes of the derivatives of the rational Bezier paths and the rational rectangular Bezier surface patches of arbitrary degree, which improve previous work of this type in many cases. Moreover, our new bounds are explicitly given by simple and closed-form expressions. An important advantage of the closed-form expressions is that they allow us to prove that our bounds are sharp under certain well-defined conditions. Some numerical examples, highlighting the potential of the new bounds in providing improved estimates, are given in an appendix. (C) 2013 Elsevier Inc. All rights reserved.
ELSEVIER SCIENCE INC, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.amc.2013.09.039
DOI ID:10.1016/j.amc.2013.09.039, ISSN:0096-3003, eISSN:1873-5649, Web of Science ID:WOS:000327765600041 - Global Nonlinear Brascamp-Lieb Inequalities
Jonathan Bennett; Neal Bez; Susana Gutierrez
JOURNAL OF GEOMETRIC ANALYSIS, 巻:23, 号:4, 開始ページ:1806, 終了ページ:1817, 2013年10月, [査読有り]
We prove global versions of certain known nonlinear Brascamp-Lieb inequalities under a natural homogeneity assumption. We also establish a conditional theorem allowing one to generally pass from local to global nonlinear Brascamp-Lieb estimates under such a homogeneity assumption.
SPRINGER, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1007/s12220-012-9307-3
DOI ID:10.1007/s12220-012-9307-3, ISSN:1050-6926, Web of Science ID:WOS:000325065700009 - On derivative bounds for the rational quadratic Bezier paths
H. E. Bez; N. Bez
COMPUTER AIDED GEOMETRIC DESIGN, 巻:30, 号:2, 開始ページ:254, 終了ページ:261, 2013年02月, [査読有り]
New derivative bounds for the rational quadratic Bezier paths are obtained, both for particular weight vectors and for classes of equivalent parametrisations. A comprehensive analysis of our bounds against existing bounds is made. (C) 2012 Elsevier B.V. All rights reserved.
ELSEVIER SCIENCE BV, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.cagd.2012.12.003
DOI ID:10.1016/j.cagd.2012.12.003, ISSN:0167-8396, Web of Science ID:WOS:000316037900006 - Transversal multilinear Radon-like transforms: local and global estimates
Jonathan Bennett; Neal Bez; Susana Gutierrez
REVISTA MATEMATICA IBEROAMERICANA, 巻:29, 号:3, 開始ページ:765, 終了ページ:788, 2013年, [査読有り]
We prove local "L-P-improving" estimates for a class of multi-linear Radon-like transforms satisfying a strong transversality hypothesis. As a consequence, we obtain sharp multilinear convolution estimates for measures supported on fully transversal submanifolds of Euclidean space of arbitrary dimension. Motivated by potential applications in diffraction tomography, we also prove global estimates for the same class of Radon-like transforms under a natural homogeneity assumption.
EUROPEAN MATHEMATICAL SOC, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.4171/RMI/739
DOI ID:10.4171/RMI/739, ISSN:0213-2230, Web of Science ID:WOS:000326990500002 - A sharp Strichartz estimate for the wave equation with data in the energy space
Neal Bez; Keith M. Rogers
JOURNAL OF THE EUROPEAN MATHEMATICAL SOCIETY, 巻:15, 号:3, 開始ページ:805, 終了ページ:823, 2013年, [査読有り]
We prove a sharp bilinear estimate for the wave equation from which we obtain the sharp constant in the Strichartz estimate which controls the L-t, x(4)(R5+1) norm of the solution in terms of the energy. We also characterise the maximisers.
EUROPEAN MATHEMATICAL SOC, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.4171/JEMS/377
DOI ID:10.4171/JEMS/377, ISSN:1435-9855, Web of Science ID:WOS:000317564700005 - A majorant problem for the periodic Schrodinger group
J. Bennett; N. Bez
RIMS Kokyuroku Bessatsu, 巻:B33, 開始ページ:1, 終了ページ:10, 2012年, [査読有り] - Some nonlinear Brascamp-Lieb inequalities and applications to harmonic analysis
Jonathan Bennett; Neal Bez
JOURNAL OF FUNCTIONAL ANALYSIS, 巻:259, 号:10, 開始ページ:2520, 終了ページ:2556, 2010年11月, [査読有り]
We use the method of induction-on-scales to prove certain diffeomorphism-invariant nonlinear Brascamp-Lieb inequalities. We provide applications to multilinear convolution inequalities and the restriction theory for the Fourier transform, extending to higher dimensions recent work of Bejenaru-Herr-Tataru and Bennett-Carbery-Wright. (C) 2010 Elsevier Inc. All rights reserved.
ACADEMIC PRESS INC ELSEVIER SCIENCE, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1016/j.jfa.2010.07.015
DOI ID:10.1016/j.jfa.2010.07.015, ISSN:0022-1236, Web of Science ID:WOS:000281532200002 - Heat-flow monotonicity related to the Hausdorff-Young inequality
Jonathan Bennett; Neal Bez; Anthony Carbery
BULLETIN OF THE LONDON MATHEMATICAL SOCIETY, 巻:41, 開始ページ:971, 終了ページ:979, 2009年12月, [査読有り]
It is known that if q is an even integer, then the L(q)(R(d)) norm of the Fourier transform of a superposition of translates of a fixed gaussian is monotone increasing as their centres 'simultaneously slide' to the origin. We provide explicit examples to show that this monotonicity property fails dramatically if q > 2 is not an even integer. These results are equivalent, upon rescaling, to similar statements involving solutions to heat equations. Such considerations are natural given the celebrated theorem of Beckner concerning the gaussian extremisability of the Hausdorff-Young inequality.
OXFORD UNIV PRESS, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1112/blms/bdp073
DOI ID:10.1112/blms/bdp073, ISSN:0024-6093, Web of Science ID:WOS:000272924700002 - MAXIMAL OPERATORS AND HILBERT TRANSFORMS ALONG FLAT CURVES NEAR L-1
Neal Bez
JOURNAL OF THE AUSTRALIAN MATHEMATICAL SOCIETY, 巻:87, 号:3, 開始ページ:311, 終了ページ:323, 2009年12月, [査読有り]
For a class of convex curves in R-d we prove that the corresponding maximal operator and Hilbert transform are of weak type L log L. The point of interest here is that this class admits Curves which are infinitely flat at the origin. We also prove in analogous weak type result for a class of nonconvex hypersurfaces.
CAMBRIDGE UNIV PRESS, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1017/S1446788709000111
DOI ID:10.1017/S1446788709000111, ISSN:1446-7887, Web of Science ID:WOS:000273957500002 - Closure Properties of Solutions to Heat Inequalities
Jonathan Bennett; Neal Bez
JOURNAL OF GEOMETRIC ANALYSIS, 巻:19, 号:3, 開始ページ:584, 終了ページ:600, 2009年07月, [査読有り]
We prove that if u(1), u(2) : (0, infinity) x R(d) -> (0, infinity) are sufficiently well-behaved solutions to certain heat inequalities on Rd then the function u : (0, infinity) x R(d) -> (0, infinity) given by u(1/p) = u(1)(1/p1) * u(2)(1/p2) also satisfies a heat inequality of a similar type provided 1/p1 + 1/p2 = 1 + 1/p. On iterating, this result leads to an analogous statement concerning n-fold convolutions. As a corollary, we give a direct heat-flow proof of the sharp n-fold Young convolution inequality and its reverse form.
SPRINGER, 英語, 研究論文(学術雑誌)
DOI:https://doi.org/10.1007/s12220-009-9070-2
DOI ID:10.1007/s12220-009-9070-2, ISSN:1050-6926, Web of Science ID:WOS:000265214800005 - Heat-flow monotonicity underlying some sharp inequalities in geometric and harmonic analysis
N. Bez
RIMS Kokyuroku Bessatsu, 巻:B14, 開始ページ:1, 終了ページ:16, 2009年, [査読有り]
京都大学, 英語
ISSN:1881-6193, CiNii Articles ID:110007480919, CiNii Books ID:AA12196120 - HEAT-FLOW MONOTONICITY OF STRICHARTZ NORMS
Jonathan Bennett; Neal Bez; Anthony Carbery; Dirk Hundertmark
ANALYSIS & PDE, 巻:2, 号:2, 開始ページ:147, 終了ページ:158, 2009年, []
Our main result is that for d = 1, 2 the classical Strichartz norm parallel to e(is Delta) f parallel to(2+4/d)(Ls,x)(RxR(d)) associated to the free Schrodinger equation in nondecreasing as the initial datum f evolves under a certain quadratic heat flow.
MATHEMATICAL SCIENCE PUBL
ISSN:1948-206X, Web of Science ID:WOS:000281883500002 - Maximal Operators along Piecewise Linear Curves near L-1
Neal Bez
INDIANA UNIVERSITY MATHEMATICS JOURNAL, 巻:58, 号:4, 開始ページ:1639, 終了ページ:1657, 2009年, []
For certain piecewise linear plane curves F and convex functions Phi we address the question of whether the maximal operator along Gamma is of weak type Phi(L). For example, when F is the graph of the continuous map y for which Y(2(k)) = 2(2k) and y is linear on [2(k), 2(k+1)], k is an element of Z, then the maximal operator along Gamma is not of weak type L(logL)sigma for any sigma is an element of (0, 1/2).
INDIANA UNIV MATH JOURNAL
DOI:https://doi.org/10.1512/iumj.2009.58.3606
DOI ID:10.1512/iumj.2009.58.3606, ISSN:0022-2518, Web of Science ID:WOS:000269448000006 - Mixed-norm estimates for a class of nonisotropic directional maximal operators and Hilbert transforms
Neal Bez
JOURNAL OF FUNCTIONAL ANALYSIS, 巻:255, 号:12, 開始ページ:3281, 終了ページ:3302, 2008年12月, []
For all d >= 2 and P epsilon (1, max(2, (d + 1)/2)], we prove sharp L(p) to L(p)(L(q)) estimates (modulo an endpoint) for a directional maximal operator associated to curves generated by the dilation matrices exp((log t)P), where P has real entries and eigenvalues with positive real part. For the corresponding Hilbert transform we prove an analogous result for all d >= 2 and P epsilon (1, 2]. As corollaries, we prove L(p) bounds for variable kernel singular integral operators and Nikodym-type maximal operators taking averages over certain families of curved sets in R(d). (C) 2008 Elsevier Inc. All rights reserved.
ACADEMIC PRESS INC ELSEVIER SCIENCE
DOI:https://doi.org/10.1016/j.jfa.2008.07.026
DOI ID:10.1016/j.jfa.2008.07.026, ISSN:0022-1236, Web of Science ID:WOS:000261578900003 - L-p-boundedness for the Hilbert transform and maximal operator along a class of nonconvex curves
Neal Bez
PROCEEDINGS OF THE AMERICAN MATHEMATICAL SOCIETY, 巻:135, 号:1, 開始ページ:151, 終了ページ:161, 2007年, []
Some sufficient conditions on a real polynomial P and a convex function gamma are given in order for the Hilbert transform and maximal operator along ( t, P gamma( t))) to be bounded on L-p, for all p in ( 1, infinity), with bounds independent of the coefficients of P. The same conclusion is shown to hold for the corresponding hypersurface in Rd+1 ( d >= 2) under weaker hypotheses on gamma.
AMER MATHEMATICAL SOC
DOI:https://doi.org/10.1090/S0002-9939-06-08603-5
DOI ID:10.1090/S0002-9939-06-08603-5, ISSN:0002-9939, Web of Science ID:WOS:000240542200020
- 滑らかさを加味した直交ストリッカーツ評価 (関数空間の一般化とその周辺)
BEZ NEAL; HONG YOUNGHUN; LEE SANGHYUK; 中村 昌平; 澤野 嘉宏
数理解析研究所講究録 = RIMS Kokyuroku, 号:2143, 開始ページ:173, 終了ページ:184, 2019年12月
直交ストリッカーツ評価と呼ばれる新しい評価を示す. 最初に, FrankとSabinによる関数の滑らかさを加味しない直交ストリッカーツ評価[5]を示し, 後で我々による関数の滑らかさを加味した直交ストリッカーツ評価のひとつの場合の証明する. この結果は我々の論文[2]として出版されている.
京都大学数理解析研究所
ISSN:1880-2818, CiNii Articles ID:120006888263, CiNii Books ID:AN00061013
■ 共同研究・競争的資金等の研究課題
- 基底状態の諸相に対する多角的探究の試み
日本学術振興会, 科学研究費助成事業, 基盤研究(A), 2022年04月01日 - 2027年03月31日
杉本 充; 高橋 太; BEZ NEAL, 名古屋大学
配分額(総額):38740000, 配分額(直接経費):29800000, 配分額(間接経費):8940000
課題番号:22H00098 - Investigating the stability of the inverse Brascamp-Lieb inequality
日本学術振興会, 基盤研究(B), 2023年04月 - 2027年03月
Neal Bez, 研究代表者
課題番号:23K25777 - 幾何的極大作用素に対する端点評価
日本学術振興会, 科学研究費助成事業, 特別研究員奨励費, 2023年11月 - 2026年03月
BEZ NEAL; GAUVAN ANTHONY, 埼玉大学
配分額(総額):1600000, 配分額(直接経費):1600000
課題番号:23KF0188 - 古典場の理論における微分型相互作用の数学解析
日本学術振興会, 科学研究費助成事業, 基盤研究(A), 2019年04月01日 - 2024年03月31日
小澤 徹; 田中 和永; 町原 秀二; BEZ NEAL, 早稲田大学
配分額(総額):43680000, 配分額(直接経費):33600000, 配分額(間接経費):10080000
微分型シュレディンガー方程式をはじめとする微分型相互作用を持つ古典場模型の非線型偏微分方程式は、ピカール逐次近似の枠組において、必然的に微分の損失を伴うため、その回避を巡って方程式に応じた個別の方法論が提案されているが、未だに本質的な理解に至っていない。本研究の目的は、近年の微分型シュレディンガー方程式の初期値問題の時間大域的存在を保障する新しい閾値の変分解析的理解を足掛かりとして、微分型相互作用の大域的構造を(a)漸近解析、(b)調和解析、(c)変分解析の三つの方法論に基づいて明らかにする事である。
令和2年度は、漸近解析班は半古典近似と爆発解の研究を中心に、調和解析班はストリッカーズ評価と正規直交系の研究を中心に、変分解析班は古典軌道の存在と一意性の研究を中心に進めた。
半古典近似に関しては、対数型非線型項を持つシュレディンガー方程式の漸近公式を得た。爆発解に関しては、複素係数を持つ非線型シュレディンガー方程式の大域解の非存在定理を得た。ストリッカーズ評価に関しては、自乗可積分函数の成すヒルベルト空間の正規直交系を用いる定式化を改良した。
古典軌道の一意性に関しては、始点と終点の長さで完全に特徴づけ、臨界幅の区間では無限個の周期軌道が発生する事を示した。一意性と存在に関しては、等式の枠組で定式化した新たなポワンカレの不等式を本質的に証明で用いた。ここで用いられた新しいポワンカレの不等式の定式化に関しては等質群をはじめとした様々な空間において一般化した。
課題番号:19H00644 - 分散方程式と調和解析学の研究
日本学術振興会, 科学研究費助成事業, 国際共同研究加速基金(国際共同研究強化(B)), 2018年10月09日 - 2023年03月31日
小澤 徹; 田中 和永; BEZ NEAL; 内田 俊; 湯浅 一哉, 早稲田大学
配分額(総額):17810000, 配分額(直接経費):13700000, 配分額(間接経費):4110000
当該年度も引き続きCOVID-19の影響により、研究代表者・分担者・協力者がピサ大学および早稲田大学に集まることは叶わず、研究遂行上に大きな支障となった。しかし、このような状況下でも、オンライン会議を用いて進捗状況・途中経過・部分的成果等を共有し、活発に意見交換を行うとともに、今後の研究の方向性について検討を重ねることで、一定の成果を得る事ができた。具体的に述べると、次の通りである。
楕円型方程式の解析の基礎を支えるポワンカレの不等式に関しては、等式の枠組で定式化し、その剰余項を用いた最大化函数の非存在の新しい証明を与えた。
トーラス上の非線型シュレディンガー方程式に関しては、今までほとんど取り上げられていなかったゲージ不変でない二次の自己相互作用の研究に着手し、一次元トーラスの結果の多次元化を進めている。手始めに、二次元の問題について、大域解の非存在につながる初期データのクラスについての部分的な結果が得られたので、引き続き一般化を検討する計画である。
量子マスター方程式に関しては、「マクスウェルの悪魔」と呼ばれる現象の新たな定式化に、この方程式の解析が有効であることを見出し、電流制御の視点から理論体系を完成させた。
流体の速度場を記述するブリンクマン・フォルシュハイマー方程式系として知られている二重拡散移流方程式系に関しては、3次元および4次元の全空間において、時間周期解の存在を示し、考える領域の有界性が本質的でないことを実証した。
課題番号:18KK0073 - New perspectives on space-time estimates for dispersive equations
日本学術振興会, 基盤研究(B), 2019年04月 - 2023年03月
Neal Bez, 研究代表者
課題番号:19H01796 - 多重線形解析を用いたフーリエ変換の制限問題の新展開
日本学術振興会, 科学研究費助成事業, 特別研究員奨励費, 2018年04月25日 - 2020年03月31日
BEZ NEAL; CUNANAN JAYSON MESITAS, 埼玉大学
配分額(総額):1500000, 配分額(直接経費):1500000
Based on techniques arising in the restriction theory of the Fourier transform, several new results were obtained concerning the kinetic transport equation and the wave equation. For the kinetic transport equation, in the case where the velocities belong to the sphere and radially symmetric square-integrable initial data, sharp results were obtained for mixed-norm estimates on velocity averages in the framework of hyperbolic Sobolev spaces. In a different direction, the Keel-Tao approach was used to obtain new inhomogeneous Strichartz estimates of weak type for the wave equation where the so-called acceptability condition fails.
課題番号:18F18020 - 等式の枠組による零形式の時空大域的研究
日本学術振興会, 科学研究費助成事業, 挑戦的萌芽研究, 2016年04月01日 - 2020年03月31日
小澤 徹; 田中 和永; BEZ NEAL, 早稲田大学
配分額(総額):3640000, 配分額(直接経費):2800000, 配分額(間接経費):840000
零形式の時空大域的研究の根底を支える球面上への跡定理の安定性について、その双対性による特徴づけと最良不等式が得られた。ハーディーの不等式とレリッヒの不等式に対しては、等式の枠組みで定式化し、剰余項を明示するとともに、最良定数と最適化函数の直接的具体的な理解を呈示することができた。これは、従来の背理法やコンパクト性に基づく間接的な理解を一新する方法論であり、今後の発展に繋がるものである。
課題番号:16K13771 - Conjectures associated with Brascamp-Lieb type inequalities
日本学術振興会, 若手研究(A), 2016年04月 - 2019年03月
Neal Bez, 研究代表者
競争的資金, 課題番号:16H05995 - New frontiers in kinetic equation theory
日本学術振興会, 研究活動スタート支援, 2014年08月 - 2016年03月
Neal Bez, 研究代表者
競争的資金, 課題番号:26887008