Lilac (19962015)
Baxter (20012017)
Dora (2015 )
Office Address
Departments of Mathematics
Hokkaido University
North 10, West 8, Kitaku,
Sapporo, 0600810, JAPAN
hterao00((at))za3.sonet.ne.jp
My vita
is here (PDF 87KB : as of 2018.01.09)
Books
 Arrangements of Hyperplanes
. (xviii
+ pp.325) (Peter Orlik, Hiroaki Terao) Grundlehren der
mathmetischen Wissenschaften 300, SpringerVerlag, BerlinHeidelbergNew
York; ISBN10: 3540552596 ISBN13: 9783540552598, 1992
 Arrangements  Tokyo 1998. (pp.278)
Proceedings of an MSJRegional Workshop
on Mathematics Related to Arrangements of
Hyperplanes, Tokyo Metropolitan Univ., 1998,
Advanced
Studies in Pure Math., 27,
(ed. M. Falk, H. Terao) , Kinokuniya, Tokyo;
ISBN10: 4314101407
ISBN13: 9784314101400, 2000
 Arrangements and
hypergeometric integrals. (ix + pp.112)
(Peter Orlik, Hiroaki Terao) MSJ Memoir, 9,
Math. Soc. Japan, Tokyo; ISBN:
4931469108 ISBN13:9784931469105, 2001/2007 (second edition)
(This book may be hard to come by.
Contact me at hterao00(at)za3.sonet.ne.jp if you would like to get
a copy of this.)
 不変量とはなにか
― 現代数学のこころ (pp.246)
(今井 淳・寺尾宏明・中村博昭著) ブルーバックス 1393,
講談社 ; ISBN: 4062573938, Nov. 2002
 不変量と対称性: 現代数学のこころ (pp.292)
(今井 淳・寺尾宏明・中村博昭著) ちくま学芸文庫,
筑摩書房 ; ISBN: 4480095217, Mar. 2013
(本書は『不変量とはなにか ― 現代数学のこころ』(今井 淳・寺尾宏明・中村博昭著，ブルーバックス 1393，講談社) の改訂版です．)
正誤表 (2018.02.20)
 線形代数 ― 講義と演習(pp. 171)
(小林正典・寺尾宏明著)
培風館 ; ISBN: 9784563003739, Apr. 2007
正誤表 (2010.04.16)

Arrangements of Hyperplanes
 Sapporo, 2009. (pp.570)
Proceedings of the Second MSJSI, Hokkaido University,
Sapporo, 2009,
Advanced Studies in Pure Math.,
62,
(ed. H. Terao, S. Yuzvinsky), Math. Soc. of Japan,
Tokyo;
ISBN：9784931469679,
March 2012
 線形代数 ― 講義と演習 改訂版(pp. 189)
(小林正典・寺尾宏明著)
培風館 ; ISBN: 9784563004873, Feb. 2014
Publications

Forms with logarithmic pole and the filtration by the order of the pole.
Proc. Intern. Sympo. on Algebraic Geometry
Kyoto, 1977, Kinokuniya, Tokyo, 1978, 673685

The rational forms on the weighted projective space and the filtration by the order of pole.
Sci. Papers of the Coll. of Gen. Ed. Univ. of Tokyo
28, no.2 (1978), 153158
URI: http://hdl.handle.net/2261/21140

Arrangements of hyperplanes and their freeness I.
J. Fac. Sci. Univ. Tokyo Sect. 1 A, Math.
27 (1980), 293312
URI: http://hdl.handle.net/2261/6266

Arrangements of hyperplanes and their freeness II the Coxetor equality.
J. Fac. Sci. Univ. Tokyo Sect. 1 A, Math.
27 (1980), 313320
URI: http://hdl.handle.net/2261/6267

Free arrangements and unitary reflection groups.
Proc. Japan Acad., Ser. A, Math. Sci.
56, no.8 (1980), 389392
doi: 10.3792/pjaa.56.389

Generalized exponents of a free arrangement of hyperplanes and ShephardToddBrieskorn formula.
Inventiones math.
63, no.1 (1981), 159179
doi: 10.1007/BF01389197

On Betti numbers of complement of hyperplanes.
Publ. Res. Inst. Math. Sci.
17, no.2 (1981), 657663
doi: 10.2977/prims/1195185267

The exponents of a free hypersurface.
Proc. Symp. Pure Math. Singularities, part 2,
40 (1983), 561566
doi: 10.1090/pspum/040.2/713280

The bifurcation set and logarithmic vector fields.
Math. Ann.
263, no.3 (1983), 313321
doi: 10.1007/BF01457134

Les treilles hypersolvables et les arrangements des hyperplans libres.
(M. Jambu, H.Terao)
C. R. Acad. Sci. Paris Ser. I Math.
296 (1983), 623624

Free arrangements of hyperplanes over an arbitrary field.
Proc. Japan Acad. Ser. A Math. Sci.
59, no.7 (1983), 301303
doi: 10.3792/pjaa.59.301

Discriminant of a holomorphic map and logarithmic vector fields.
J. Fac. Sci. Univ., Univ. of Tokyo. Sect. 1 A, Math.
30 (1983), 379391
URI: http://hdl.handle.net/2261/6382

Free arrangements of hyperplanes and supersolvable lattices.
(M. Jambu, H. Terao)
Advancesin Math.
52, no.3 (1984), 248258
doi: 10.1016/00018708(84)900240

The duality of the exponents of free deformations associated with unitary reflection groups. Algebraic Groups and Related Topics,
(H. Terao, T. Yano)
Advanced Studies in Pure Math.
6 (1984), Kinokuniya and NorthHolland, TokyoAmsterdam,
347359

Arrangements of hyperplanes and differential forms.
(P. Orlik, L. Solomon, H. Terao)
Contemporary Math.
34 (1984), Amer. Math. Soc., Providence, R.I.,2965

On the Coxeter arrangement and the Coxeter number.
(P. Orlik, L. Solomon, H. Terao)
Advanced Studies in Pure Math.
8, Complex Analytic Singularities, Kinokuniya and NorthHolland,TokyoAmsterdam, 1986, 461477

Modular elements of lattices and topological fibration.
Advances in Math.
62, no.2 (1986), 133154
doi: 10.1016/00018708(86)900976

A formula for the characteristic polynomial of an arrangement.
(L. Solomon, H. Terao)
Advances in Math.
64, no.3 (1987), 305325
doi: 10.1016/00018708(87)900119

Arrangements of hyperplanes and brokencircuits.
(M. Jambu, H. Terao)
Contemporary Math.
90, Amer. Math. Soc., Providence, R.I., 1989, 147162
doi: 10.1090/conm/090

Basic derivations for {\G_34} : Appendix to "Basic derivations for unitary reflection groups" by P. Orlik.
(H. Terao, Y. Enta)
Contemporary Math.
90 (1989), Amer. Math. Soc., Providence, R.I., 225227
doi: 10.1090/conm/090
Print ISBN: 9780821850961, Electronic ISBN: 9780821876787

The Jacobians and the discriminants of finite reflection groups.
Tohoku Math. J.
41, no. 2 (1989), 237247
doi: 10.2748/tmj/1178227822

On a certain invariant of a finite unitary reflection group.
Proc. Japan Acad. Ser. A
65 (1989), 320322
doi: 10.3792/pjaa.65.320

Hilbert polynomials and geometric lattices.
(L. Rose, H. Terao)
Advances in Math.
84, no.2 (1990), 209225
doi: 10.1016/00018708(90)90045O

A free resolution of the module of logarithmic forms of a generic arrangement.
(L. Rose, H. Terao)
J. of Algebra
136, no.2 (1991), 376400
doi: 10.1016/00218693(91)90052A

Factorizations of the OrlikSolomon Algebras.
Advances in Math.
91, no.1 (1992), 4553
doi: 10.1016/00018708(92)90009A

Coxeter arrangements are hereditarily free.
(P. Orlik, H. Terao)
Tohoku Math. J.
45, no. 3 (1993), 369383
doi: 10.2748/tmj/1178225890

Free arrangements and relation spaces.
(K. Brandt, H. Terao)
Discrete Comput. Geom.
12 (1994), 4963
doi: 10.1007/BF02574365

Commutative algebras for arrangements.
(P. Orlik, H. Terao)
Nagoya J. of Math.
134 (1994), 6573
doi: 10.1017/S0027763000004852

Arrangements and Milnor fibers.
(P. Orlik, H. Terao)
Math. Ann.
301 (1995), 211235
doi: 10.1007/BF01446627

Logarithmic forms on affine arrangements.
(H. Terao, S. Yuzvinsky)
Nagoya J. of Math.
139 (1995), 129149
doi: 10.1017/S002776300000533X

The number of critical points of a product of powers of linear functions.
(P. Orlik, H. Terao)
Inventiones Math.
120 (1995), 114
doi: 10.1007/BF01241120

Local systems over complements of hyperplanes and the KacKazhdan conditions for
singular vectors.
(V. Schechtman, H. Terao, A. Varchenko)
J. Pure and Applied Alg. Physics and Algebra
100 (1995), 93102
doi:10.1016/00224049(95)00014N

The logarithmic forms of $k$generic arrangements.
(K.S. Lee, H. Terao)
J. Math. Sci. Univ. of Tokyo
3 (1996), 8389
doi:10.1007/BF02362574

$\beta{\bf nbc}$bases for cohomology of local systems on hyperplane complements.
(M. Falk, H. Terao)
Transactions AMS
349 (1997), 189202
doi:10.1090/S0002994797018448

The determinant of a hypergeometric period matrix.
(A. Douai, H. Terao)
Inventiones Math.
128 (1997), 417436
doi:10.1007/s002220050146

Twisted de Rham cohomology groups of logarithmic forms.
(K. Aomoto, M. Kita, P. Orlik, H. Terao)
Advances in Math.
128 (1997), 119152
doi:10.1006/aima.1997.1631

The double Coxeter arrangements.
(L. Solomon, H. Terao)
Comment. Math. Helv.
73 (1998), 237258
doi:10.1007/s000140050054

Logarithmic forms and antiinvariant forms of reflection groups.
(A. Shepler, H. Terao)
Advanced Studies in Pure Math.
27, 273278, ArrangementsTokyo 1998 (eds. M. Falk and H. Terao), Kinokuniya, Tokyo,2000
 Moduli space of
combinatorially equivalent arrangements of hyperplanes
and logarithmic GaussManin connections.
Topology and its
appl. 118 (2002), 255274
doi:10.1016/S01668641(01)000542
 Multiderivations of
Coxeter arrangements.
Inventiones mathematicae 148 (2002), 659674
doi:10.1007/s002220100209
 Algebras generated by
reciprocals of linear forms.
Journal of Algebra
250 (2002), 549558
doi:10.1006/jabr.2001.9121
 The Poincar\'e series
of the algebra of rational functions which are
regular outside hyperplanes. (H. Horiuchi, H. Terao)
Journal of Algebra
266 (2003), 169179
doi:10.1016/S00218693(03)003302
 Bases of the contactorder filtration of derivations of Coxeter
arrangements.
Proc. AMS
133 (2005), 20292034
doi: 10.1090/S0002993905077671
 The Hodge filtration and the contactorder filtration of
derivations of Coxeter arrangements.
Manuscripta Math.
118 (2005), 19
doi: 10.1007/s002290040536z
 EdelmanReiner予想の解決について.
第６回代数群と量子群の表現論研究集会報告集, 2003, 101110
(PDF 93KB)
 超平面配置と ranking 数学と社会科学のひとつの接点.
第４８回代数学シンポジウム報告集, 2003, 6977
(PDF 88KB)
 Arrangements and ranking patterns.
(H. Kamiya, P. Orlik, A. Takemura, H. Terao)
Annals of Combinatorics,
10 (2006), 219235
doi: 10.1007/s0002600602848
 超平面配置と特異点.
「数学のたのしみ」, 2005, 秋, 日本評論社, 6579
 超平面配置入門
特に、自由超平面配置について .
数理研講究録 1501, 2006, 19,
(PDF 88KB)
URI: http://hdl.handle.net/2433/58436

Chambers of Arrangements of
Hyperplanes and Arrow's Impossibility Theorem.
Advances in Math. 214 (2007), 366378
doi: 10.1016/j.aim.2007.02.006
 The characteristic polynomial of a
multiarrangement.
(T. Abe, H. Terao, M. Wakefield)
Advances in Math. 215 (2007), 825838
doi: 10.1016/j.aim.2007.04.019
 The Euler
multiplicity
and the additiondeletion theorems for
multiarrangements.
(T. Abe, H. Terao, M. Wakefield)
J. London Math. Soc. (2)
77
(2008), 335348
doi: 10.1112/jlms/jdm110

A correction to ``Bases of the contactorder filtration of
derivations of Coxeter arrangements.''
Proc. Amer. Math. Soc.
136
(2008), 26392639
doi: 10.1090/S000299390809477X
 Periodicity of hyperplane arrangements
with integral coefficients modulo positive integers.
(H. Kamiya, A. Takemura, H. Terao)
J. Alg. Combin.
27
(2008), 317330
doi: 10.1007/s1080100700912

Totally free arrangements of hyperplanes.
(T. Abe, H. Terao, M. Yoshinaga)
Proc. Amer. Math. Soc.
137
(2009), 14051410
doi:0.1090/S0002993908097554
 The characteristic quasipolynomials of
the arrangements of root systems and midhyperplane arrangements.
(H. Kamiya, A. Takemura, H. Terao)
in:
``Arrangements, local systems and singularities,''
Lecture Notes of a 2007 CIMPA Summer School held at
Galatasaray University (Istanbul), Jun. 1122, 2007,
(ed. F. Elzein, A. Suciu, M. Tosun, A. M. Uludag, S. Yuzvinsky),
Progress in Math.
283, Birkhauser, 177190, 2010, ISBN:9783034602082
doi: 10.1007/9783034602099_7

A primitive derivation and logarithmic differential forms
of Coxeter arrangements.
(T. Abe, H. Terao)
Math. Z.
264
(2010), 813828
doi: 10.1007/s0020900904898

Primitive filtrations of the modules of
invariant logarithmic forms of Coxeter arrangements.
(T. Abe, H. Terao)
Journal of Algebra,
330
(2011), 251262
doi: 10.1016/j.jalgebra.2010.12.010

Ranking patterns of unfolding models of codimension one.
(H. Kamiya, A. Takemura, H. Terao)
Advances in Applied Mathematics,
47
(2011), 379400
doi: 10.1016/j.aam.2010.11.002

The freeness of ShiCatalan arrangements.
(T. Abe, H. Terao)
European J. Combin.
32
(2011), 11911198
doi: 10.1016/j.ejc.2011.06.005
 Periodicity of noncentral integral arrangements modulo positive integers.
(H. Kamiya, A. Takemura, H. Terao)
Annals of Combinatorics,
15
(2011), 449464
doi: 10.1007/s0002601101056

The Shi arrangement of the type $D_\ell$.
(R. Gao, D. Pei, H. Terao)
Proc. Japan Acad. Ser. A Math. Sci.,
88
(2012), 4145
doi: 10.3792/pjaa.88.41

Equivariant multiplicities of Coxeter arrangements and invariant bases.
(T. Abe, H. Terao, A. Wakamiko)
Advances in Math.
230
(2012), 23642377
doi: 10.1016/j.aim.2012.04.015

The Shi arrangements and the Bernoulli polynomials.
(D. Suyama, H. Terao)
Bull. London Math. Soc.
44
(2012), 563570
doi: 10.1112/blms/bdr118

Arrangements stable under the Coxeter groups.
(H. Kamiya, A. Takemura, H. Terao)
in:
``Configuration Spaces: Geometry, Combinatorics and Topology,''
Proceedings of a special period
at the De Giorgi Center,
Scuola Normale in Pisa, May  June, 2010,
(ed. A. Bjorner, F. Cohen, C. De Concini, C. Procesi, M. Salvetti),
Edizioni Della Normale, Pisa, 327354, 2012, ISBN:9788876424304
doi: 10.1007/9788876424311_15
 Weyl 配置のイデアル部分配置の自由性.
数理研講究録 1870, 2013, 115126, ISSN:18802818
(PDF 181KB)
URI: http://hdl.handle.net/2433/195440

The freeness of ideal subarrangements of Weyl arrangements.
(T. Abe, M. Barakat, M. Cuntz, T. Hoge, H. Terao )
in:
DMTCS Proceedings of "26th International Conference on Formal Power Series and Algebraic Combinatorics (FPSAC 2014)"
AT
(2014), 501512
 数学通信 巻頭言.
数学通信 第18巻4号, 2014, 34
(PDF 210KB)
 数学 論説「超平面配置に関する最近の話題」．
(H. Terao, M. Yoshinaga)
数学 第66巻第2号, 2014年春季号, 157179

Simpleroot bases for Shi arrangements.
(T. Abe, H. Terao)
Journal of Algebra
422
(2015), 89104
doi: 10.1016/j.jalgebra.2014.09.011

Free filtrations of affine Weyl arrangements and the idealShi arrangements.
(T. Abe, H. Terao)
J. Algebraic Combin.
43
(2016), 3344
doi:10.1007/s108010150624z

The freeness of ideal subarrangements of Weyl arrangements.
(T. Abe, M. Barakat, M. Cuntz, T. Hoge, H. Terao)
J. Eur. Math. Soc.
18
(2016), 13391348
doi: 10.4171/JEMS/615

Canonical systems of basic invariants for unitary reflection groups.
(N. Nakashima, H. Terao, S. Tsujie)
Canad. Math. Bull.
59, no.3 (2016), 617623
doi: 10.4153/CMB20160317

Logarithmic vector fields for curve configurations in $P^2$ with quasihomogeneous singularities.
(arXiv:1407.3237)
(H. Schenck, H. Terao, M. Yoshinaga)
Math. Res. Lett.
(to appear)

Multiple addition, deletion and restriction theorems for hyperplane arrangements(arXiv:1801.01790)
(T. Abe, H. Terao)
Research Interest
 Arrangements of hyperplanes,
especially relations with local system cohomology and
hypergeometric functions, Reflection groups
Talks (2005)

Free arrangements of hyperplanes,
Periods
Around the Theory of Primitive Forms
In Honor of Professor Kyoji Saito on his Sixtieth Birthday,
Research Institute for Mathematical Sciences (RIMS)
Kyoto University,
January 26, 2005

Arrangements of hyperplanes and hypergeometric integrals
(Video),
Applications of singularities workshop at CIRM,
Marseille Luminy, February 7, 2005

What makes arrangements free?
Euroconferences in Mathematics on Crete,
Algebraic and Geometric Combinatorics,
Anogia, Greece, August 21, 2005

超平面配置入門  特に、自由超平面配置について ,
Recent Topics on Real and Complex Singularities,
Research Institute for Mathematical Sciences (RIMS)
Kyoto University,
November 28, 2005

Multiderivations of Coxeter Arrangements of Type $B_\ell$
and Primitive Derivations,
Colloquium,
Northern Arizona University,
Feb. 17, 2006

Various phases of arrangements of hyperplanes,
Colloquium, Hokkaido
University, April 28, 2006

Multiderivations of real reflection arrangements,
The international
symposium on singularity theory and their applications II, Beijing
University of Chemical Technology, China, May 10, 2006

カタラン数の語る数学の世界
(Enumerative Combinatorics 入門)
北海道大学高校生講座
Jul. 31, 2006

Multiderivations of Coxeter Arrangements of Type $B_\ell$
and Primitive Derivations,
Geometry and Analysis on Complex Algenbraic Varieties,
Joint RFBRJSPS Symposium,
Moscow Independent University,
Aug. 17, 2006

Chambers of arrangements of hyperplanes and
Arrow's impossibility theorem,
Development of Computational Algebraic Statistics,
Research Institute for Mathematical Sciences (RIMS)
Kyoto University,
Nov. 8, 2006

Chambers of arrangements of hyperplanes and
Arrow's impossibility theorem,
Colloquium,
Okayama University,
Nov. 9, 2006

Basic properties of multiarrangements,
Geometry and analysis on complex varieties,
Research Institute for Mathematical Sciences (RIMS)
Kyoto University,
Dec. 13, 2006

Chambers of arrangements of hyperplanes and
Arrow's impossibility theorem,
American Mathematical Society, Annual Meeting,
special session on Arrangements and Related Topics,
New Orleans Sheraton, New Orleans, LA, USA,
Jan. 6, 2007.
(slides available in pdf format)

Chambers of arrangements of hyperplanes and
Arrow's impossibility theorem,
Braids and their Ramifications 
Configuration Spaces, Arrangements, Mapping, MappingClass groups, 3Manifolds,
Cortona, Italy,
May 24, 2007.
(slides available: download
this file (dvi).
You also need to download and save
this file
as zu1.eps.)

The characteristic polynomials of (multi)arrangements,
CIMPA summer school ALS \& S 2007,
Arrangements and Local Systems,
Istanbul, Turkey,
June 15, 2007.

The characteristic quasipolynomial of integral
arrangements and root systems,
CIMPA summer school ALS \& S 2007,
Arrangements and Local Systems,
Istanbul, Turkey,
June 15, 2007.

Periodicity of integral arrangements modulo positive integers,
Several Aspects of Hyperplane Arrangements,
Kobe, Japan,
Feb. 4, 2008.

On the free multiarrangements,
Several Aspects of Hyperplane Arrangements,
1037TH American Mathematical Society Meeting,
special session on Arrangements and Related Topics,
Louisiana State University, Baton Rouge, LA, USA,
Mar. 28, 2008

On the free multiarrangements,
Millican Lecture, Colloquium,
University of North Texas, May 2, 2008

Totally free arrangements of hyperplanes,
Conference in Honour of Peter Orlik,
Fields Institute, Toronto, Canada,
Aug. 19, 2008

Periodicity of hyperplane arrangements
with integral coefficients modulo positive integers,
Finite Groups, vertex operator algebras and
combinatorics,
RIMS, Kyoto University,
Jan. 6, 2009

Mathematics related to hyperplane arrangements,
Geometry of singularities and related topics,
Tokyo University of Science,
Mar. 13, 2010

Mathematics related to hyperplane arrangements,
special onehour lecture by an Algebra Prize recipient,
MSJ Annual Meeting, Keio
University, Yokohama,
Mar. 26, 2010

Combinatorial and algebrogeometric properties of free arrangements,
an invited onehour talk,
Workshop on
"Algebra and Geometry of
Configuration Spaces and related structures"
June 21  25, 2010,
Centro di ricerca matematica Ennio De Giorgi,
Pisa, Italy,
June 22, 2010

The Shi arrangements and the Bernoulli numbers,
an invited talk at the
Special Session on
"The Algebraic Geometry and
Topology of Hyperplane Arrangements"
at
an AMS Sectional Meeting,
April 910, 2011,
College of the Holy Cross, Worcester, MA, USA,
April 9, 2011

Simple bases for the logarithmic derivation modules
of the generalized Shi arrangements,
an invited talk at
"Topics in the Theory of Weyl Groups and Root Systems
(Sekiguchi 60),"
September 2022, 2011,
University of Tokyo,
September 20, 2011

Primitive derivations, Shi arrangements
and Bernoulli polynomials.
an invited talk at the
Special Session on
"Singularities,
Stratifications and their Applications"
at
an AMS Sectional Meeting,
March 34, 2012,
University of Hawaii Manoa, Honolulu, HI, USA,
March 3, 2012 (with D. Suyama)

Height basis of Weyl arrangements.
an invited talk at the
"Arrangements in Pyrenees"
School on hyperplane arrangements and related topics,
June 1115, 2012, Universite de Pau, France, June 11, 2012

Primitive derivations, Shi arrangements,
Bernoulli polynomials and the
heightfree conjecture.
an invited onehour talk at the
"FPSAC '12 (The 24th International Conference on Formal
Power Series and Algebraic Combinatorics),"
July 30August 3, 2012, Nagoya University, August 2, 2012

Primitive derivations, Shi arrangements
and
Bernoulli polynomials.
an invited talk at the
"2012 Shanghai Conference on Algebraic Combinatorics,"
August 17  22, 2012, Shanghai Jiao Tong University,
August 20, 2012.

Primitive derivations, Shi arrangements and Bernoulli polynomials.
a colloquium talk at Northeastern Normal University, Chanchun,
September 28, 2012.

Logarithmic derivation modules of Shi arrangements associated with root systems.
an invited talk at "Combinatorial Representation Theory and Related Topics,"
October 912, 2012, RIMS, Kyoto University, October 11, 2012.

Logarithmic derivation modules of Shi arrangements associated with root systems.
an invited talk at Workshop on "Free Divisors and Differential Equations,"
November 510, 2012, Tokyo University of Agriculture and Technology, November 8, 2012.

Logarithmic derivation modules of Shi arrangements associated with root systems.
an invited talk at Conference on "Hyperplane Arrangements: Combinatorial and Geometric Aspects,"
February 2122, 2013, RuhrUniversitat Bochum, Germany, February 21, 2013.

The freeness of ideal subarrangements of Weyl arrangements.
an invited talk at Conference on "The 6th Pacific RIM Conference on
Mathematics 2013,” July 15, 2013, Sapporo Convention Center, July 2,
2013.

Multiple addition/deletion theorems and the existence
of free paths in the affine Weyl arrangements.
Combinatorics Seminar, Nagoya University,
July 11, 2013.

On ideal subarrangements of Weyl arrangements.
an invited talk at Conference on "Hyperplane arrangements
and characteristic classes," November 1115, 2013, RIMS,
Kyoto University, November 12, 2013.

On ideal subarrangements of Weyl arrangements.
an invited talk at Conference on "Japanese Turkish Joint Geometry Meeting," November 2124, 2013, Galatasaray University, Istanbul, Turkey, November 22, 2013.

On ideal subarrangements of Weyl arrangements.
an invited lecture at CIMPAUNESCOMESRMINECOVIETNAM research school on "Geometry and Topology of Singular Varieties. Theory and Applications," December 214, 2013, the Institute of Mathematics, Vietnam Academy of Science and Technology, Hanoi, Vietnam, December, 2013,
the first and second lectures (December 23, 2013, PDF 6.7MB),
the third lecture (December 5, 2013, PDF 3MB),
the fourth lecture (December 6, 2013, PDF 506KB).

The freeness of idealShi arrangements and free paths in affine Weyl arrangements (and a question).
an invited talk at Workshop on "New perspectives in hyperplane and reflection arrangements," February 10, 2014, RuhrUniversitaet Bochum, Germany, February 10, 2014.

On ideal subarrangements of Weyl arrangements.
FPSAC '14 (The 26th International Conference on Formal Power Series and Algebraic Combinatorics),
June 29July 3, 2014, DePaul University, Chicago, USA, June 30, 2014.

On ideal subarrangements of Weyl arrangements.
an invited talk at "The 13th International Workshop in Real and Complex Singularities,"
July 27  August 1st, 2014, Instituto de Ciencias Matematicas e de Computacao
Universidade de Sao Paulo, Campus Sao Carlos, Sao Paulo, Brasil, July 28, 2014.

Chambers of Arrangements and Arrow's Impossibility Theorem.
Workshop at "Recent developments on geometrical and algebraic
methods in Economics," August 22  24, 2014, Hokkaido University,
August 22, 2014.

Ideals of the roots posets and a new proof of the dualpartition formula
by ShapiroSteinbergKostantMacdonlald.
an invited talk at "The 2nd
FrancoJapaneseVietnamese Symposium on Singularities," August 25 
29, Hokkaido University, August 26, 2014.

Multiple addition theorem on arrangements of hyperplanes and a proof
of the ShapiroSteinbergKostantMacdonald dualpartition formula.
an invited talk at "The 1st Workshop of JSPSMAE Sakura Program
"Geometry and Combinatorics of Hyperplane Arrangements and Related
Problems"," September 1  5, Hokkaido University, September 3, 2014.

Free filtrations of affine arrangements of infinitely many hyperplanes.
an invited talk at "Hokkaido University  University of Bremen Joint Seminar
"Arrangements of Hyperplanes"," December 1  3, University of Bremen, December 1, 2014.

Ideal Free Theorem and Saturated Free Filtrations of Affine Weyl Arrangements.
an invited talk at "The 10th Kagoshima AlgebraAnalysisGeometry Seminar,"
February 16  19, Kagoshima University, February 17, 2015.

Arrangements of hyperplanes and applications.
an invited special talk, Korea Advanced Institute of Science and Technology, March 13, 2015.

Ideal Free Theorem and Saturated Free Filtrations of AffineWeyl
Arrangements.
an invited talk at "Algebraic structures in combinatorics and geometry," June 6  12, RIMS, Kyoto University, June 11, 2015.

Ideal Free Theorem and Saturated Free Filtrations os Affine Weyl Arrangements.
an invited talk at "Computational Geometric Topology in Arrangement Theory," July 6  10,
ICERM, Brown University, USA, July 10, 2015.

On Parabolic Subarrangements and Restrictions of Weyl arrangements.
an invited talk at "Differential and combinatorial aspects of singularities," August 3  7,
Technische Universitaet Kaiserslautern, Germany, August 7, 2015.

Before and After the Idealfree Theorem.
an invited talk at "Hyperplane arrangements and reflection groups,"
August 10  12, Leibniz Universitaet Hannover, Germany, August 11, 2015.

Multiple addition theorem on arrangements of hyperplanes
and a proof of the ShapiroSteinbergKostantMacdonald
dualpartition formula.
an invited talk at "Braids, Configuration Spaces, and Quantum Topology,"
September 7  10, the University of Tokyo, September 8, 2015.

Subarrangements and restrictions of Weyl arrangements.
an invited talk at the Special Session on "Topology and Combinatorics of Arrangements (in honor of Mike Falk)" at an AMS Spring Eastern Sectional Meeting, March 19  20, Stony Brook University, USA, March 19, 2016.

Reflection Arrangements and Free Arrangements.
an invited onehour talk at ``Perspectives in Algebraic Topology,
A day in honor of Mario Salvetti on the occasion of his 60th birthday,''
June 5, University of Pisa, Italy, 2017.

Multiple Addition/Deletion Theorems. II.
an invited talk at ``Advances in Arrangement Theory,
Mathematical Congress of the Americas (MCA) 2017,''
Montreal, Canada, July 25, 2017.
Prize
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