How do load multiples child views in the same page

I have nested views inside the main.html template that are not showing the h1 message.

this is my routes

.config(function($stateProvider, $urlRouterProvider){

$urlRouterProvider.otherwise('/');

$stateProvider

.state('login',{
    url: '/',
    templateUrl: 'templates/login.html',
    controller:'loginController'
})

.state('main', {
    url: 'main',
    templateUrl: 'templates/main.html'
})

.state('main.categories', {
    url: '/categories',
    views: {
        'main-categories': {
            templateUrl: 'templates/main-categories.html',
            controller: 'categoriesController'
        }
    }
})

.state('main.products', {
    url: '/products',
    views: {
        'main-products': {
            templateUrl: 'templates/main-products.html',
            controller: 'productsController'
        }
    }
})

.state('main.tickets', {
    url: '/tickets',
    views: {
        'main-tickets': {
            templateUrl: 'templates/main-tickets.html',
            controller: 'ticketsController'
        }
    }
})

})

the state main has child views of main.categories, main.products and main.tickets. This is my main.html template holding the child views

<div class="bar bar-header">
<button class="button button-icon icon ion-navicon"></button>
<div class="h1 title">Header Buttons</div>
<button class="button button-clear button-positive">Edit</button>
</div>
<!--categories-->
<div class="col-20">
    <ion-nav-view name="main-categories"></ion-nav-view>
</div>

<!--products-->
<div class="col-60">
    <ion-nav-view name="main-products"></ion-nav-view>
</div>

<!--tickets-->
<div class="col-20">
    <ion-nav-view name="main-tickets"></ion-nav-view>
</div>

</div>

this is what i have in the main-categories child view

<h1>categories</h1>

this is what i have in the main-products child view

<h1>products</h1>

this is what i have in the main-tickets child view

<h1>tickets</h1>

i want those 3 child views to diplay child when i go to the /main url. what am I doing wrong ?