BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Mahir Bilen Can (Tulane University) DTSTART:20210726T130000Z DTEND:20210726T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/1 DESCRIPTION:Title: Lecture 1: Lie Groups and Algebraic Groups in Action\nby Mahir Bilen Can (Tulane University) as part of GGTI Online Seminars\n\n\nA bstract\nThe purpose of our lectures is to give a short but self-contained overview of some well-known results about the geometry of algebraic group actions. We will focus mainly on the actions of connected reductive group s. Our main goals are 1) introducing some interesting examples of equivari ant completions of homogeneous spaces\, 2) explaining several combinatoria l gadgets such as valuation cones\, weight monoids\, colors\, etc. that ar e not only useful for classifying algebraic actions of low complexity but also essential for understanding these equivariant completions. Along the way\, we will review some representation theory. In addition\, we will ana lyze some concrete examples of combinatorial varieties such as toric and S chubert varieties.\n\nZoom Meeting ID 974 3685 2246\n\nPassword Initials o f the speaker's name (use capitals)\n\nŞifre Konuşmacının adının ba ş harfleri (büyük harflerle) \n\nhttps://gokovagt.org/institute/doku.ph p?id=lecture:2021:mahir_bilen_can\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/1/ END:VEVENT BEGIN:VEVENT SUMMARY:Mahir Bilen Can (Tulane University) DTSTART:20210727T130000Z DTEND:20210727T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/2 DESCRIPTION:Title: Lecture 2: Lie Groups and Algebraic Groups in Action\nby Mahir Bilen Can (Tulane University) as part of GGTI Online Seminars\n\n\nA bstract\nThe purpose of our lectures is to give a short but self-contained overview of some well-known results about the geometry of algebraic group actions. We will focus mainly on the actions of connected reductive group s. Our main goals are 1) introducing some interesting examples of equivari ant completions of homogeneous spaces\, 2) explaining several combinatoria l gadgets such as valuation cones\, weight monoids\, colors\, etc. that ar e not only useful for classifying algebraic actions of low complexity but also essential for understanding these equivariant completions. Along the way\, we will review some representation theory. In addition\, we will ana lyze some concrete examples of combinatorial varieties such as toric and S chubert varieties.\n\nZoom Meeting ID 974 3685 2246\n\nPassword Initials o f the speaker's name (use capitals)\n\nŞifre Konuşmacının adının ba ş harfleri (büyük harflerle) \n\nhttps://gokovagt.org/institute/doku.ph p?id=lecture:2021:mahir_bilen_can\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/2/ END:VEVENT BEGIN:VEVENT SUMMARY:Mahir Bilen Can (Tulane University) DTSTART:20210728T130000Z DTEND:20210728T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/3 DESCRIPTION:Title: Lecture 3: Lie Groups and Algebraic Groups in Action\nby Mahir Bilen Can (Tulane University) as part of GGTI Online Seminars\n\n\nA bstract\nThe purpose of our lectures is to give a short but self-contained overview of some well-known results about the geometry of algebraic group actions. We will focus mainly on the actions of connected reductive group s. Our main goals are 1) introducing some interesting examples of equivari ant completions of homogeneous spaces\, 2) explaining several combinatoria l gadgets such as valuation cones\, weight monoids\, colors\, etc. that ar e not only useful for classifying algebraic actions of low complexity but also essential for understanding these equivariant completions. Along the way\, we will review some representation theory. In addition\, we will ana lyze some concrete examples of combinatorial varieties such as toric and S chubert varieties.\n\nZoom Meeting ID 974 3685 2246\n\nPassword Initials o f the speaker's name (use capitals)\n\nŞifre Konuşmacının adının ba ş harfleri (büyük harflerle) \n\nhttps://gokovagt.org/institute/doku.ph p?id=lecture:2021:mahir_bilen_can\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/3/ END:VEVENT BEGIN:VEVENT SUMMARY:Mahir Bilen Can (Tulane University) DTSTART:20210729T130000Z DTEND:20210729T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/4 DESCRIPTION:Title: Lecture 4: Lie Groups and Algebraic Groups in Action\nby Mahir Bilen Can (Tulane University) as part of GGTI Online Seminars\n\n\nA bstract\nThe purpose of our lectures is to give a short but self-contained overview of some well-known results about the geometry of algebraic group actions. We will focus mainly on the actions of connected reductive group s. Our main goals are 1) introducing some interesting examples of equivari ant completions of homogeneous spaces\, 2) explaining several combinatoria l gadgets such as valuation cones\, weight monoids\, colors\, etc. that ar e not only useful for classifying algebraic actions of low complexity but also essential for understanding these equivariant completions. Along the way\, we will review some representation theory. In addition\, we will ana lyze some concrete examples of combinatorial varieties such as toric and S chubert varieties.\n\nZoom Meeting ID 974 3685 2246\n\nPassword Initials o f the speaker's name (use capitals)\n\nŞifre Konuşmacının adının ba ş harfleri (büyük harflerle) \n\nhttps://gokovagt.org/institute/doku.ph p?id=lecture:2021:mahir_bilen_can\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/4/ END:VEVENT BEGIN:VEVENT SUMMARY:Mahir Bilen Can (Tulane University) DTSTART:20210730T130000Z DTEND:20210730T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/5 DESCRIPTION:Title: Lecture 5: Lie Groups and Algebraic Groups in Action\nby Mahir Bilen Can (Tulane University) as part of GGTI Online Seminars\n\n\nA bstract\nThe purpose of our lectures is to give a short but self-contained overview of some well-known results about the geometry of algebraic group actions. We will focus mainly on the actions of connected reductive group s. Our main goals are 1) introducing some interesting examples of equivari ant completions of homogeneous spaces\, 2) explaining several combinatoria l gadgets such as valuation cones\, weight monoids\, colors\, etc. that ar e not only useful for classifying algebraic actions of low complexity but also essential for understanding these equivariant completions. Along the way\, we will review some representation theory. In addition\, we will ana lyze some concrete examples of combinatorial varieties such as toric and S chubert varieties.\n\nZoom Meeting ID 974 3685 2246\n\nPassword Initials o f the speaker's name (use capitals)\n\nŞifre Konuşmacının adının ba ş harfleri (büyük harflerle) \n\nhttps://gokovagt.org/institute/doku.ph p?id=lecture:2021:mahir_bilen_can\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/5/ END:VEVENT BEGIN:VEVENT SUMMARY:Joé Brendel (University of Neuchâtel) DTSTART:20210823T130000Z DTEND:20210823T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/6 DESCRIPTION:Title: Lecture 1: The Delzant construction\nby Joé Brendel (Uni versity of Neuchâtel) as part of GGTI Online Seminars\n\n\nAbstract\nTori c symplectic manifolds are symplectic manifolds with an effective Hamilton ian torus action of maximal dimension. Toric manifolds are distinguished b y the property that they can be reconstructed from a combinatorial object called the moment polytope. Thus they are a great playground for symplecti c topology and the study of Lagrangian submanifolds\, since complicated in variants may be reduced to combinatorial properties of the corresponding m oment polytope. In recent years\, there has been much interest in a genera lization called “almost toric” structures.\n\nIn these four lectures\, we will introduce these two classes of symplectic manifolds\, and use the ir special structure to study Lagrangian tori and symplectic embedding pro blems.\n\nPlease find the Zoom ID/password from the seminar homepage:\n\nh ttps://gokovagt.org/institute/doku.php?id=lecture:2021:joe_brendel_felix_s chlenk\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/6/ END:VEVENT BEGIN:VEVENT SUMMARY:Joé Brendel (University of Neuchâtel) DTSTART:20210824T130000Z DTEND:20210824T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/7 DESCRIPTION:Title: Lecture 2: Versal deformations and the Chekanov torus\nby Joé Brendel (University of Neuchâtel) as part of GGTI Online Seminars\n \n\nAbstract\nToric symplectic manifolds are symplectic manifolds with an effective Hamiltonian torus action of maximal dimension. Toric manifolds a re distinguished by the property that they can be reconstructed from a com binatorial object called the moment polytope. Thus they are a great playgr ound for symplectic topology and the study of Lagrangian submanifolds\, si nce complicated invariants may be reduced to combinatorial properties of t he corresponding moment polytope. In recent years\, there has been much in terest in a generalization called “almost toric” structures.\n\nIn the se four lectures\, we will introduce these two classes of symplectic manif olds\, and use their special structure to study Lagrangian tori and symple ctic embedding problems.\n\nPlease find the Zoom ID/password from the semi nar homepage:\n\nhttps://gokovagt.org/institute/doku.php?id=lecture:2021:j oe_brendel_felix_schlenk\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/7/ END:VEVENT BEGIN:VEVENT SUMMARY:Felix Schlenk (University of Neuchâtel) DTSTART:20210825T130000Z DTEND:20210825T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/8 DESCRIPTION:Title: Lecture 3: Almost toric symplectic fibrations\nby Felix S chlenk (University of Neuchâtel) as part of GGTI Online Seminars\n\n\nAbs tract\nToric symplectic manifolds are symplectic manifolds with an effecti ve Hamiltonian torus action of maximal dimension. Toric manifolds are dist inguished by the property that they can be reconstructed from a combinator ial object called the moment polytope. Thus they are a great playground fo r symplectic topology and the study of Lagrangian submanifolds\, since com plicated invariants may be reduced to combinatorial properties of the corr esponding moment polytope. In recent years\, there has been much interest in a generalization called “almost toric” structures.\n\nIn these four lectures\, we will introduce these two classes of symplectic manifolds\, and use their special structure to study Lagrangian tori and symplectic em bedding problems.\n\nPlease find the Zoom ID/password from the seminar hom epage:\n\nhttps://gokovagt.org/institute/doku.php?id=lecture:2021:joe_bren del_felix_schlenk\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/8/ END:VEVENT BEGIN:VEVENT SUMMARY:Felix Schlenk (University of Neuchâtel) DTSTART:20210826T130000Z DTEND:20210826T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/9 DESCRIPTION:Title: Lecture 4: Three applications (maximal embeddings of ellipsoi ds\, exotic Lagrangian tori\, and non-isotopic cube embeddings)\nby Fe lix Schlenk (University of Neuchâtel) as part of GGTI Online Seminars\n\n \nAbstract\nToric symplectic manifolds are symplectic manifolds with an ef fective Hamiltonian torus action of maximal dimension. Toric manifolds are distinguished by the property that they can be reconstructed from a combi natorial object called the moment polytope. Thus they are a great playgrou nd for symplectic topology and the study of Lagrangian submanifolds\, sinc e complicated invariants may be reduced to combinatorial properties of the corresponding moment polytope. In recent years\, there has been much inte rest in a generalization called “almost toric” structures.\n\nIn these four lectures\, we will introduce these two classes of symplectic manifol ds\, and use their special structure to study Lagrangian tori and symplect ic embedding problems.\n\nPlease find the Zoom ID/password from the semina r homepage:\n\nhttps://gokovagt.org/institute/doku.php?id=lecture:2021:joe _brendel_felix_schlenk\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/9/ END:VEVENT BEGIN:VEVENT SUMMARY:Eylem Zeliha Yildiz (Duke University) DTSTART:20210927T130000Z DTEND:20210927T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/10 DESCRIPTION:Title: Lecture 1: Shaking Knots\nby Eylem Zeliha Yildiz (Duke U niversity) as part of GGTI Online Seminars\n\n\nAbstract\n"Knot Shaking" i s a technique introduced $44$ years ago as a tool to study exotic smoothin gs of $4$-manifolds with boundary. Let be $K$ be a knot\, and $K^{r}$ be the $4$-manifold obtained by attaching a $2$-handle to $B^{4}$ along $K$ w ith framing $r$. We say that $K$ is $r$-shake slice if a generator of $H _{2}(K^{r})=Z$ is represented by a smoothly imbedded $2$-sphere\; this is equivalent to saying that the link consisting of $K$ and an even number of oppositely oriented parallel copies of $K$ (parallel with respect to $r$- framing) to bound disk with holes in $B^4$. Clearly slice knots are $r$-sh ake slice. It is known that when $r\\neq 0$ not all $r$-shake slice knots are slice\, and there are knots that are not $r$-shake slice. We address t he important remaining case of $r=0$\, and prove that $0$-shake slice knot s are slice. Along the way\, we discuss how shaking is related to the exot ic smooth structures and corks.\n\nZoom Meeting ID 937 1654 5820\n\nPasswo rd Initials of the speaker's name (use capitals)\n\nŞifre Konuşmacının adının baş harfleri (büyük harflerle)\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/10/ END:VEVENT BEGIN:VEVENT SUMMARY:Selman Akbulut (GGTI) DTSTART:20210928T130000Z DTEND:20210928T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/11 DESCRIPTION:Title: Lecture 2: Shaking Knots\nby Selman Akbulut (GGTI) as pa rt of GGTI Online Seminars\n\n\nAbstract\n"Knot Shaking" is a technique in troduced $44$ years ago as a tool to study exotic smoothings of $4$-manifo lds with boundary. Let be $K$ be a knot\, and $K^{r}$ be the $4$-manifold obtained by attaching a $2$-handle to $B^{4}$ along $K$ with framing $r$. We say that $K$ is $r$-shake slice if a generator of $H_{2}(K^{r})=Z$ i s represented by a smoothly imbedded $2$-sphere\; this is equivalent to sa ying that the link consisting of $K$ and an even number of oppositely orie nted parallel copies of $K$ (parallel with respect to $r$-framing) to boun d disk with holes in $B^4$. Clearly slice knots are $r$-shake slice. It is known that when $r\\neq 0$ not all $r$-shake slice knots are slice\, and there are knots that are not $r$-shake slice. We address the important rem aining case of $r=0$\, and prove that $0$-shake slice knots are slice. Alo ng the way\, we discuss how shaking is related to the exotic smooth struct ures and corks.\n\nZoom Meeting ID 912 1482 3818\n\nPassword Initials of t he speaker's name (use capitals)\n\nŞifre Konuşmacının adının baş h arfleri (büyük harflerle)\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/11/ END:VEVENT BEGIN:VEVENT SUMMARY:Grigory Mikhalkin (University of Geneva) DTSTART:20211019T130000Z DTEND:20211019T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/12 DESCRIPTION:Title: Lecture 1: Logarithmic images of algebraic curves in the rea l plane\nby Grigory Mikhalkin (University of Geneva) as part of GGTI O nline Seminars\n\n\nAbstract\nThese lectures are devoted to real algebraic curves in real algebraic surfaces and to areas delimited by these curves. We will start with several basic notions and facts in topology of real al gebraic curves and surfaces paying a particular attention to algebraic cur ves in the real plane. The discussion around amoebas and areas of these cu rves will naturally lead us to the notion of simple Harnack curves. After the study of various properties of simple Harnack curves\, we will present analogs of these curves in the framework of $K3$-surfaces and will finish the lectures by introducing areas of connected components of the real poi nt set of a real $K3$-surface (using a holomorphic symplectic form of the surface) and establishing certain inequalities for these areas.\n\nThe top ics of the lectures are tentative. We encourage the audience to participat e actively by interrupting the lecturers and asking questions. The actual content of the lectures will depend on these interactions.\n\nZoom Meeting ID 952 4893 3373\n\nPassword Initials of the speaker's name (use capitals )\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/12/ END:VEVENT BEGIN:VEVENT SUMMARY:Ilia Itenberg (Sorbonne University) DTSTART:20211020T130000Z DTEND:20211020T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/13 DESCRIPTION:Title: Lecture 2: Topology of real algebraic curves and surfaces\nby Ilia Itenberg (Sorbonne University) as part of GGTI Online Seminars\ n\n\nAbstract\nThese lectures are devoted to real algebraic curves in real algebraic surfaces and to areas delimited by these curves. We will start with several basic notions and facts in topology of real algebraic curves and surfaces paying a particular attention to algebraic curves in the real plane. The discussion around amoebas and areas of these curves will natur ally lead us to the notion of simple Harnack curves. After the study of va rious properties of simple Harnack curves\, we will present analogs of the se curves in the framework of $K3$-surfaces and will finish the lectures b y introducing areas of connected components of the real point set of a rea l $K3$-surface (using a holomorphic symplectic form of the surface) and es tablishing certain inequalities for these areas.\n\nThe topics of the lect ures are tentative. We encourage the audience to participate actively by i nterrupting the lecturers and asking questions. The actual content of the lectures will depend on these interactions.\n\nZoom Meeting ID 949 1884 34 38\n\nPassword Initials of the speaker's name (use capitals)\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/13/ END:VEVENT BEGIN:VEVENT SUMMARY:Grigory Mikhalkin (University of Geneva) DTSTART:20211021T130000Z DTEND:20211021T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/14 DESCRIPTION:Title: Lecture 3: Amoebas\, coamoebas and simple Harnack curves \nby Grigory Mikhalkin (University of Geneva) as part of GGTI Online Semin ars\n\n\nAbstract\nThese lectures are devoted to real algebraic curves in real algebraic surfaces and to areas delimited by these curves. We will st art with several basic notions and facts in topology of real algebraic cur ves and surfaces paying a particular attention to algebraic curves in the real plane. The discussion around amoebas and areas of these curves will n aturally lead us to the notion of simple Harnack curves. After the study o f various properties of simple Harnack curves\, we will present analogs of these curves in the framework of $K3$-surfaces and will finish the lectur es by introducing areas of connected components of the real point set of a real $K3$-surface (using a holomorphic symplectic form of the surface) an d establishing certain inequalities for these areas.\n\nThe topics of the lectures are tentative. We encourage the audience to participate actively by interrupting the lecturers and asking questions. The actual content of the lectures will depend on these interactions.\n\nZoom Meeting ID 952 489 3 3373\n\nPassword Initials of the speaker's name (use capitals)\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/14/ END:VEVENT BEGIN:VEVENT SUMMARY:Ilia Itenberg (Sorbonne University) DTSTART:20211022T130000Z DTEND:20211022T140000Z DTSTAMP:20260422T213046Z UID:GGTI-online-seminars/15 DESCRIPTION:Title: Lecture 4: Areas in K3-surfaces\nby Ilia Itenberg (Sorbo nne University) as part of GGTI Online Seminars\n\n\nAbstract\nThese lectu res are devoted to real algebraic curves in real algebraic surfaces and to areas delimited by these curves. We will start with several basic notions and facts in topology of real algebraic curves and surfaces paying a part icular attention to algebraic curves in the real plane. The discussion aro und amoebas and areas of these curves will naturally lead us to the notion of simple Harnack curves. After the study of various properties of simple Harnack curves\, we will present analogs of these curves in the framework of $K3$-surfaces and will finish the lectures by introducing areas of con nected components of the real point set of a real $K3$-surface (using a ho lomorphic symplectic form of the surface) and establishing certain inequal ities for these areas.\n\nThe topics of the lectures are tentative. We enc ourage the audience to participate actively by interrupting the lecturers and asking questions. The actual content of the lectures will depend on th ese interactions.\n\nZoom Meeting ID 949 1884 3438\n\nPassword Initials of the speaker's name (use capitals)\n LOCATION:https://researchseminars.org/talk/GGTI-online-seminars/15/ END:VEVENT END:VCALENDAR